Replacing digit words into digits - java

I am trying to replace all digit words zero-nine into their corresponding digits 0-9 in a string.
I have created the two arrays of digit words and digits and then trying for loop with a replace to change the sentence.
Not sure what i am doing wrong.
I'm referencing my getNoDigitWordString method.
import java.util.*;
public class StringProcessor {
private String noSpaces;
private String input, noVowels;
private String noDigitWords;
private int numOfWords = 0, uppercaseLetters = 0,
numOfDigits = 0, digitWords = 0;
private String [] wordDigits = {"zero","one", "two", "three","four",
"five", "six", "seven", "eight", "nine"};
private String [] digits = {"0", "1", "2", "3", "4",
"5", "6", "7", "8", "9"};
public StringProcessor()
{
input = "";
}
public StringProcessor(String s)
{
StringTokenizer str = new StringTokenizer(s);
numOfWords = str.countTokens();
for (int i = 0; i < s.length(); i++)
{
if (Character.isUpperCase(s.charAt(i)))
uppercaseLetters++;
}
for (int i = 0; i < s.length(); i++)
{
if (Character.isDigit(s.charAt(i)))
numOfDigits++;
}
String [] strSplit = s.split(" ");
for(int i = 0; i < strSplit.length; i++)
{
for (int j = 0; j < wordDigits.length; j++)
{
if (strSplit[i].equalsIgnoreCase(wordDigits[j]))
digitWords++;
}
}
noSpaces = s.replace(" ","");
noVowels = s.replaceAll("[aeiou]", "-");
for(int i = 0; i < 10; i++)
{
noDigitWords = s.replace("wordDigits[i]", "digits[i]");
}
}
public void setString(String s)
{
input = s;
}
public String getString()
{
return input;
}
public int wordCount()
{
return numOfWords;
}
public int uppercaseCount()
{
return uppercaseLetters;
}
public int digitCount()
{
return numOfDigits;
}
public int digitWordCount()
{
return digitWords;
}
public String getNoSpaceString()
{
return noSpaces;
}
public String getNoVowelString()
{
return noVowels;
}
public String getNoDigitWordString()
{
return noDigitWords;
}
public static void main(String[] args)
{
String input;
Scanner keyboard = new Scanner(System.in);
System.out.print("Enter a line of text: ");
input = keyboard.nextLine();
StringProcessor str = new StringProcessor(input);
System.out.println("words: " + str.wordCount());
System.out.println("uppercase: " + str.uppercaseCount());
System.out.println("digits: " + str.digitCount());
System.out.println("digit words " + str.digitWordCount());
System.out.println("line with no spaces: " + str.getNoSpaceString());
System.out.println("line with vowels replaced: " + str.getNoVowelString());
System.out.println("line with digit words replaced: " + str.getNoDigitWordString());
}
}
Thanks.

This is what you're looking for:
noDigitWords = s;
for(int i = 0; i < strSplit.length; i++)
{
for (int j = 0; j < wordDigits.length; j++)
{
if (strSplit[i].equalsIgnoreCase(wordDigits[j])){
noDigitWords = noDigitWords.replace(strSplit[i], digits[j]);
break;
}
}
}
Instead of this:
for(int i = 0; i < 10; i++)
{
noDigitWords = s.replace("wordDigits[i]", "digits[i]");
}

Aside from the problem #dcharms pointed out, this is not going to work:
for(int i = 0; i < 10; i++)
{
noDigitWords = s.replace(wordDigits[i], digits[i]);
}
Here's what happens: First, you search s for "zero", and call s.replace. This returns a string with the word "zero" replaced by "0". Then that string is assigned to noDigitWords. But s itself does not change.
Then, next time through the loop, you search in the original s for the next word. The work you did in the previous iteration, which was in noDigitWords, gets thrown away.
The result will be that the last word you search for, "nine", should get replaced. But any other replacements you've made will be thrown away.

Each time the following code calls the replace method, the string noDigitWords is overwritten.
for(int i = 0; i < 10; i++)
{
noDigitWords = s.replace("wordDigits[i]", "digits[i]");
}
After the final iteration of the loop, the string "one nine" becomes "one 9" rather than "1 9" as desired. The solution is to call the replace method on the return value of the previous iteration of the loop. Initialize the string noDigitWords to the value of the string s. Each iteration do the replace on noDigitWords as shown below.
noDigitWords = s;
for(int i = 0; i < 10; i++)
{
noDigitWords = noDigitWords.replace(wordDigits[i], digits[i]);
}

Try replacing noDigitWords = s.replace("wordDigits[i]", "digits[i]"); with noDigitWords = s; outside for loop and
noDigitWords = noDigitWords.replaceAll(wordDigits[i], digits[i]); inside.
Your original was looking for a string "wordDigits[i]" instead of the contents of wordDigits[i]. Your output had a similar issue.

Related

How do I get my output to contain the spaces I need?

I have to capitalize the first letter in every word passed into the string. My output is doing that capitalization, but it's not maintaining the format of the original output. For example, string input is "hello world", my output is "HelloWorld", and my desired output should be "Hello World."
I've tried to add spaces where I can throughout the code but nothing works. I think the problem is that when I use toCharArray, it gives me an output with no spaces? So my concatenation result is adding everything in one swoop, versus each word separately?
Or I thought that my code was using string concatenation with my result, and it's not being separated because I have both words going into the same variable.
import java.util.*;
import java.io.*;
class Main {
public static String LetterCapitalize(String str) {
// code goes here
String[] word = str.split(" ");
String result = "";
for(int i = 0; i < word.length; i++) {
char[] charWord = word[i].toCharArray();
for(int j = 0; j < charWord.length; j++ ) {
String cap = word[i].charAt(0) + "";
cap = cap.toUpperCase();
//System.out.print(" ");
result += (j == 0 ? cap : word[i].charAt(j));
}
}
return result;
}
public static void main (String[] args) {
// keep this function call here
Scanner s = new Scanner(System.in);
System.out.print(LetterCapitalize(s.nextLine()));
}
}
No errors. Just not getting desired output.
When you did String[] word = str.split(" ");, the space between each word is taken out and you are now left with only the words in an array. You should use String.join(" ", word) on the resultant words array to reverse the effects so you get the spaces back.
Instead of going through each word char by char, try this:
for(int i = 0; i < word.length; i++) {
word[i] = word[i].substring(0, 1).toUpperCase() + word[i].substring(1);
}
result = String.join(" ", word);
Try this:
import java.util.*;
class Main {
public static String LetterCapitalize(String str) {
// code goes here
String[] word = str.split(" ");
String result = "";
for(int i = 0; i < word.length; i++) {
result += capitalize(word[i]) + (i != word.length - 1 ? " " : "");
}
return result;
}
private static String capitalize(String s){
return Character.toUpperCase(s.charAt(0)) + s.substring(1);
}
public static void main (String[] args) {
// keep this function call here
Scanner s = new Scanner(System.in);
System.out.print(LetterCapitalize(s.nextLine()));
}
}
You can use the below code.
class Main {
public static String LetterCapitalize(String str) {
// code goes here
String[] word = str.split(" ");
StringBuilder result = new StringBuilder();
for (int i = 0; i < word.length; i++) {
char[] charWord = word[i].toCharArray();
for (int j = 0; j < charWord.length; j++) {
String cap = word[i].charAt(0) + "";
cap = cap.toUpperCase();
//System.out.print(" ");
result.append(j == 0 ? cap : word[i].charAt(j));
}
result.append(" ");
}
return result.toString();
}
public static void main(String[] args) {
// keep this function call here
Scanner s = new Scanner(System.in);
System.out.print(LetterCapitalize(s.nextLine()));
}
}

Count each element in string array

Hey guys this is my code for splitting the array first without using any inbuilt functions. It works fine, my question is in the second part.
static String[] split(String ss) {
String[] a = new String[1];
String s = "";
for (int i = 0; i < ss.length(); i++) {
if (ss.charAt(i) == ' ') {
s += ", "
} else {
s += ss.charAt(i);
}
for (int j = 0; j < a.length; j++) {
a[j] = "[" + s + "]";
}
}
return a;
}
I need now to count each letter in a word and give it out also without inbuilt functions as split, chartoarray and so on.
this is to what i came so far.
for example String="This is just an example". it should give out
This=4
is=2
..
static String[][] LettersCount(String[] array) {
int count=0;
String [][] a =new String[array.length][array.length];
String s= "" + Arrays.toString(array);
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == ' ') {
count = 0;
} else {
count++;
}
You can use property of character that it has a numerical value after all. Lets use it as index and store the counts in an array. (so we will mimic Map this way)
int[] counter = new int[256] ;// this will hold count of all letters
counter[(int) character]++; // this is how you do the counting
public class JavaArrayLengthTest {
public static void main(String[] args) {
String[] testArray = { "A", "B", "C" };
int arrayLength = testArray.length;
System.out.println("The length of the array is: " + arrayLength);
}
}

Write a method to print a string with words reversed, without the use of any standard functions [duplicate]

This question already has answers here:
Printing reverse of any String without using any predefined function?
(34 answers)
Closed 8 years ago.
I was asked this in a technical interview. I have no idea whatsoever please please help me.
it goes in infinite loop. I just cant find the correct logic.
not once, but twice i came across this kind of a question, so please help
public static int numberOfCharsInString(String sentence)
{
int numberOfChars = 0,i=0;
while (!sentence.equals(""))
{
sentence = sentence.substring(1);
++numberOfChars;
}
return numberOfChars;
}
public static void reverseSequenceOfWords(String inp)
{
int len=numberOfCharsInString(inp);
char[] in=inp.toCharArray();
int i=0;
for(i=len-1;i>=0;i--)
{
if(in[i]==' ')
{
while(!in.equals("")||in.equals(" "))
{
System.out.print(in[i]+" ");
}
}
else if(in[i]=='\0')
{
break;
}
}
}
public static void main(String[] args)
{
int length=0;
String inpstring = "";
InputStreamReader input = new InputStreamReader(System.in);
BufferedReader reader = new BufferedReader(input);
try
{
System.out.print("Enter a string to reverse:");
inpstring = reader.readLine();
length=numberOfCharsInString(inpstring);
System.out.println("Number of Characters: "+length);
reverseSequenceOfWords(inpstring);
}
catch (Exception e)
{
e.printStackTrace();
}
}
String[] array = "Are you crazy".split(" ");
for (int i = array.length - 1; i >= 0; --i) {
System.out.print(array[i] + " ");
}
Brute forced this so hard lol
public static void main (String args[]){
String input = new Scanner(System.in).nextLine();
input+=" ";
ArrayList<String> words = new ArrayList<String>();
int start = 0;
for(int i=0; i<input.length(); i++){
if(input.charAt(i)==' '){
String toAdd="";
for(int r=start; r<i; r++){
toAdd+=input.charAt(r);
}
words.add(toAdd);
start = i+1;
}
}
for(int i=words.size()-1; i>=0; i--){
System.out.print(words.get(i)+" ");
}
}
I've used String.length() and String.substring()and String.charAt() - I hope that is allowed.
private static class Word {
private final String message;
private final int start;
private final int end;
public Word(String message, int start, int end) {
this.message = message;
this.start = start;
this.end = end;
}
#Override
public String toString() {
return message.substring(start, end);
}
}
private Word[] split(String message) {
// Split it into words - there cannot be more words than characters in the message.
int[] spaces = new int[message.length()];
// How many words.
int nWords = 0;
// Pretend there's a space at the start.
spaces[0] = -1;
// Walk the message.
for (int i = 0; i < message.length(); i++) {
if (message.charAt(i) == ' ') {
spaces[++nWords] = i;
}
}
// Record the final position.
spaces[++nWords] = message.length();
// Build the word array.
Word[] words = new Word[nWords];
for (int i = 0; i < nWords; i++) {
words[i] = new Word(message, spaces[i] + 1, spaces[i + 1]);
}
return words;
}
private String reverse(String message) {
Word[] split = split(message);
String reversed = "";
for ( int i = split.length - 1; i >= 0; i--) {
reversed += split[i].toString();
if ( i > 0 ) {
reversed += " ";
}
}
return reversed;
}
public void test() {
String message = "Hello how are you today?";
System.out.println(reverse(message));
}
prints
today? you are how Hello
Much more minimal but less useful. Only uses length, charAt and substring again:
public void printWordsReversed(String message) {
int end = message.length();
for ( int i = end - 1; i >= 0; i--) {
if ( message.charAt(i) == ' ') {
System.out.print(message.substring(i+1, end)+" ");
end = i;
}
}
System.out.print(message.substring(0, end));
}
The only function i'm still using is the IndexOf function, but that is not that hard to create for yourself.
static void Main(string[] args)
{
string sentence = "are you cracy";
int length = Program.StringLength(sentence);
int currentpos = 0;
List<string> wordList = new List<string>();
int wordCount = 0;
while (currentpos < length)
{
// find the next space
int spacepos = sentence.IndexOf(' ', currentpos);
string word;
if (spacepos < 0)
{
// end of string reached.
word = sentence.Substring(currentpos, length - currentpos);
wordList.Add(word);
wordCount++;
// no need to continue.
break;
}
word = sentence.Substring(currentpos, spacepos - currentpos);
wordList.Add(word);
wordCount++;
currentpos = spacepos + 1;
}
// display
for (int i = wordList.Count - 1; i >= 0; i--)
{
// after first word is display, add spaces to the output
if (i < wordList.Count - 1)
{
Console.WriteLine(" ");
}
// display word
Console.WriteLine(wordList[i]);
}
}
public static int StringLength(String sentence)
{
int numberOfChars = 0;
while (!sentence.Equals(""))
{
sentence = sentence.Substring(1);
++numberOfChars;
}
return numberOfChars;
}

Remove repeated characters in a string

I need to write a static method that takes a String as a parameter and returns a new String obtained by replacing every instance of repeated adjacent letters with a single instance of that letter without using regular expressions. For example if I enter "maaaakkee" as a String, it returns "make".
I already tried the following code, but it doesn't seem to display the last character.
Here's my code:
import java.util.Scanner;
public class undouble {
public static void main(String [] args){
Scanner console = new Scanner(System.in);
System.out.println("enter String: ");
String str = console.nextLine();
System.out.println(removeSpaces(str));
}
public static String removeSpaces(String str){
String ourString="";
int j = 0;
for (int i=0; i<str.length()-1 ; i++){
j = i+1;
if(str.charAt(i)!=str.charAt(j)){
ourString+=str.charAt(i);
}
}
return ourString;
}
}
You could use regular expressions for that.
For instance:
String input = "ddooooonnneeeeee";
System.out.println(input.replaceAll("(.)\\1{1,}", "$1"));
Output:
done
Pattern explanation:
"(.)\\1{1,}" means any character (added to group 1) followed by itself at least once
"$1" references contents of group 1
maybe:
for (int i=1; i<str.length() ; i++){
j = i+1;
if(str.charAt(i)!=str.charAt(j)){
ourString+=str.charAt(i);
}
}
The problem is with your condition. You say compare i and i+1 in each iteration and in last iteration you have both i and j pointing to same location so it will never print the last character. Try this unleass you want to use regex to achive this:
EDIT:
public void removeSpaces(String str){
String ourString="";
for (int i=0; i<str.length()-1 ; i++){
if(i==0){
ourString = ""+str.charAt(i);
}else{
if(str.charAt(i-1) != str.charAt(i)){
ourString = ourString +str.charAt(i);
}
}
}
System.out.println(ourString);
}
if you cannot use replace or replaceAll, here is an alternative. O(2n), O(N) for stockage and O(N) for creating the string. It removes all repeated chars in the string put them in a stringbuilder.
input : abcdef , output : abcdef
input : aabbcdeef, output : cdf
private static String remove_repeated_char(String str)
{
StringBuilder result = new StringBuilder();
HashMap<Character, Integer> items = new HashMap<>();
for (int i = 0; i < str.length(); i++)
{
Character current = str.charAt(i);
Integer ocurrence = items.get(current);
if (ocurrence == null)
items.put(current, 1);
else
items.put(current, ocurrence + 1);
}
for (int i = 0; i < str.length(); i++)
{
Character current = str.charAt(i);
Integer ocurrence = items.get(current);
if (ocurrence == 1)
result.append(current);
}
return result.toString();
}
import java.util.*;
public class string2 {
public static void main(String[] args) {
//removes repeat character from array
Scanner sc=new Scanner(System.in);
StringBuffer sf=new StringBuffer();
System.out.println("enter a string");
sf.append(sc.nextLine());
System.out.println("string="+sf);
int i=0;
while( i<sf.length())
{
int j=1+i;
while(j<sf.length())
{
if(sf.charAt(i)==sf.charAt(j))
{
sf.deleteCharAt(j);
}
else
{
j=j+1;
}
}
i=i+1;
}
System.out.println("string="+sf);
}
}
Input AABBBccDDD, Output BD
Input ABBCDDA, Outout C
private String reducedString(String s){
char[] arr = s.toCharArray();
String newString = "";
Map<Character,Integer> map = new HashMap<Character,Integer>();
map.put(arr[0],1);
for(int index=1;index<s.length();index++)
{
Character key = arr[index];
int value;
if(map.get(key) ==null)
{
value =0;
}
else
{
value = map.get(key);
}
value = value+1;
map.put(key,value);
}
Set<Character> keyset = map.keySet();
for(Character c: keyset)
{
int value = map.get(c);
if(value%2 !=0)
{
newString+=c;
}
}
newString = newString.equals("")?"Empty String":newString;
return newString;
}
public class RemoveDuplicateCharecterInString {
static String input = new String("abbbbbbbbbbbbbbbbccccd");
static String output = "";
public static void main(String[] args)
{
// TODO Auto-generated method stub
for (int i = 0; i < input.length(); i++) {
char temp = input.charAt(i);
boolean check = false;
for (int j = 0; j < output.length(); j++) {
if (output.charAt(j) == input.charAt(i)) {
check = true;
}
}
if (!check) {
output = output + input.charAt(i);
}
}
System.out.println(" " + output);
}
}
Answer : abcd
public class RepeatedChar {
public static void main(String[] args) {
String rS = "maaaakkee";
String outCome= rS.charAt(0)+"";
int count =0;
char [] cA =rS.toCharArray();
for(int i =0; i+1<cA.length; ++i) {
if(rS.charAt(i) != rS.charAt(i+1)) {
outCome += rS.charAt(i+1);
}
}
System.out.println(outCome);
}
}
TO WRITE JAVA PROGRAM TO REMOVE REPEATED CHARACTERS:
package replace;
public class removingrepeatedcharacters
{
public static void main(String...args){
int i,j=0,count=0;
String str="noordeen";
String str2="noordeen";
char[] ch=str.toCharArray();
for(i=0;i<=5;i++)
{
count=0;
for(j=0;j<str2.length();j++)
{
if(ch[i]==str2.charAt(j))
{
count++;
System.out.println("at the index "+j +"position "+ch[i]+ "+ count is"+count);
if(count>=2){
str=str2;
str2=str.replaceFirst(Character.toString(ch[j]),Character.toString(' '));
}
System.out.println("after replacing " +str2);
}
}
}
}
}
String outstr = "";
String outstring = "";
for(int i = 0; i < str.length() - 1; i++) {
if(str.charAt(i) != str.charAt(i + 1)) {
outstr = outstr + str.charAt(i);
}
outstring = outstr + str.charAt(i);
}
System.out.println(outstring);
public static void remove_duplicates(String str){
String outstr="";
String outstring="";
for(int i=0;i<str.length()-1;i++) {
if(str.charAt(i)!=str.charAt(i+1)) {
outstr=outstr+str.charAt(i);
}
outstring=outstr+str.charAt(i);
}
System.out.println(outstring);
}
More fun with java 7:
System.out.println("11223344445555".replaceAll("(?<nums>.+)\\k<nums>+","${nums}"));
No more cryptic numbers in regexes.
public static String removeDuplicates(String str) {
String str2 = "" + str.charAt(0);
for (int i = 1; i < str.length(); i++) {
if (str.charAt(i - 1) == str.charAt(i) && i != 0) {
continue;
}
str2 = str2 + str.charAt(i);
}
return str2;
}

How to remove duplicate character from a string in java?

In my program, the user enters a string, and it first finds the largest mode of characters in the string. Next, my program is supposed to remove all duplicates of a character in a string, (user input: aabc, program prints: abc) which I'm not entirely certain on how to do. I can get it to remove duplicates from some strings, but not all. For example, when the user puts "aabc" it will print "abc", but if the user puts "aabbhh", it will print "abbhh." Also, before I added the removeDup method to my program, it would only print the maxMode once, but after I added the removeDup method, it began to print the maxMode twice. How do I keep it from printing it twice?
Note: I cannot convert the strings to an array.
import java.util.Scanner;
public class JavaApplication3 {
static class MyStrings {
String s;
void setMyStrings(String str) {
s = str;
}
int getMode() {
int i;
int j;
int count = 0;
int maxMode = 0, maxCount = 1;
for (i = 0; i< s.length(); i++) {
maxCount = count;
count = 0;
for (j = s.length()-1; j >= 0; j--) {
if (s.charAt(j) == s.charAt(i))
count++;
if (count > maxCount){
maxCount = count;
maxMode = i;
}
}
}
System.out.println(s.charAt(maxMode)+" = largest mode");
return maxMode;
}
String removeDup() {
getMode();
int i;
int j;
String rdup = "";
for (i = 0; i< s.length(); i++) {
int count = 1;
for (j = 0; j < rdup.length(); j++) {
if (s.charAt(i) == s.charAt(j)){
count++;
}
}
if (count == 1){
rdup += s.charAt(i);
}
}
System.out.print(rdup);
System.out.println();
return rdup;
}
}
public static void main (String[] args) {
Scanner in = new Scanner(System.in);
MyStrings setS = new MyStrings();
String s;
System.out.print("Enter string:");
s = in.nextLine();
setS.setMyStrings(s);
setS.getMode();
setS.removeDup();
}
}
Try this method...should work fine!
String removeDup()
{
getMode();
int i;
int j;
String rdup = "";
for (i = 0; i< s.length(); i++) {
int count = 1;
for (j = i+1; j < s.length(); j++) {
if (s.charAt(i) == s.charAt(j)) {
count++;
}
}
if (count == 1){
rdup += s.charAt(i);
}
}
// System.out.print(rdup);
System.out.println();
return rdup;
}
Welcome to StackOverflow!
You're calling getMode() both outside and inside of removeDup(), which is why it's printing it twice.
In order to remove all duplicates, you'll have to call removeDup() over and over until all the duplicates are gone from your string. Right now you're only calling it once.
How might you do that? Think about how you're detecting duplicates, and use that as the end condition for a while loop or similar.
Happy coding!
Shouldn't this be an easier way? Also, i'm still learning.
import java.util.*;
public class First {
public static void main(String arg[])
{
Scanner sc= new Scanner(System.in);
StringBuilder s=new StringBuilder(sc.nextLine());
//String s=new String();
for(int i=0;i<s.length();i++){
String a=s.substring(i, i+1);
while(s.indexOf(a)!=s.lastIndexOf(a)){s.deleteCharAt(s.lastIndexOf(a));}
}
System.out.println(s.toString());
}
}
You can do this:
public static void main(String[] args) {
String str = new String("PINEAPPLE");
Set <Character> letters = new <Character>HashSet();
for (int i = 0; i < str.length(); i++) {
letters.add(str.charAt(i));
}
System.out.println(letters);
}
I think an optimized version which supports ASCII codes can be like this:
public static void main(String[] args) {
System.out.println(removeDups("*PqQpa abbBBaaAAzzK zUyz112235KKIIppP!!QpP^^*Www5W38".toCharArray()));
}
public static String removeDups(char []input){
long ocr1=0l,ocr2=0l,ocr3=0;
int index=0;
for(int i=0;i<input.length;i++){
int val=input[i]-(char)0;
long ocr=val<126?val<63?ocr1:ocr2:ocr3;
if((ocr& (1l<<val))==0){//not duplicate
input[index]=input[i];
index++;
}
if(val<63)
ocr1|=(1l<<val);
else if(val<126)
ocr2|=(1l<<val);
else
ocr3|=(1l<<val);
}
return new String(input,0,index);
}
please keep in mind that each of orc(s) represent a mapping of a range of ASCII characters and each java long variable can grow as big as (2^63) and since we have 128 characters in ASCII so we need three ocr(s) which basically maps the occurrences of the character to a long number.
ocr1: (char)0 to (char)62
ocr2: (char)63 to (char)125
ocr3: (char)126 to (char)128
Now if a duplicate was found the
(ocr& (1l<<val))
will be greater than zero and we skip that char and finally we can create a new string with the size of index which shows last non duplicate items index.
You can define more orc(s) and support other character-sets if you want.
Can use HashSet as well as normal for loops:
public class RemoveDupliBuffer
{
public static String checkDuplicateNoHash(String myStr)
{
if(myStr == null)
return null;
if(myStr.length() <= 1)
return myStr;
char[] myStrChar = myStr.toCharArray();
HashSet myHash = new HashSet(myStrChar.length);
myStr = "";
for(int i=0; i < myStrChar.length ; i++)
{
if(! myHash.add(myStrChar[i]))
{
}else{
myStr += myStrChar[i];
}
}
return myStr;
}
public static String checkDuplicateNo(String myStr)
{
// null check
if (myStr == null)
return null;
if (myStr.length() <= 1)
return myStr;
char[] myChar = myStr.toCharArray();
myStr = "";
int tail = 0;
int j = 0;
for (int i = 0; i < myChar.length; i++)
{
for (j = 0; j < tail; j++)
{
if (myChar[i] == myChar[j])
{
break;
}
}
if (j == tail)
{
myStr += myChar[i];
tail++;
}
}
return myStr;
}
public static void main(String[] args) {
String myStr = "This is your String";
myStr = checkDuplicateNo(myStr);
System.out.println(myStr);
}
Try this simple answer- works well for simple character string accepted as user input:
import java.util.Scanner;
public class string_duplicate_char {
String final_string = "";
public void inputString() {
//accept string input from user
Scanner user_input = new Scanner(System.in);
System.out.println("Enter a String to remove duplicate Characters : \t");
String input = user_input.next();
user_input.close();
//convert string to char array
char[] StringArray = input.toCharArray();
int StringArray_length = StringArray.length;
if (StringArray_length < 2) {
System.out.println("\nThe string with no duplicates is: "
+ StringArray[1] + "\n");
} else {
//iterate over all elements in the array
for (int i = 0; i < StringArray_length; i++) {
for (int j = i + 1; j < StringArray_length; j++) {
if (StringArray[i] == StringArray[j]) {
int temp = j;//set duplicate element index
//delete the duplicate element by copying the adjacent elements by one place
for (int k = temp; k < StringArray_length - 1; k++) {
StringArray[k] = StringArray[k + 1];
}
j++;
StringArray_length--;//reduce char array length
}
}
}
}
System.out.println("\nThe string with no duplicates is: \t");
//print the resultant string with no duplicates
for (int x = 0; x < StringArray_length; x++) {
String temp= new StringBuilder().append(StringArray[x]).toString();
final_string=final_string+temp;
}
System.out.println(final_string);
}
public static void main(String args[]) {
string_duplicate_char object = new string_duplicate_char();
object.inputString();
}
}
Another easy solution to clip the duplicate elements in a string using HashSet and ArrayList :
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Scanner;
public class sample_work {
public static void main(String args[]) {
String input = "";
System.out.println("Enter string to remove duplicates: \t");
Scanner in = new Scanner(System.in);
input = in.next();
in.close();
ArrayList<Character> String_array = new ArrayList<Character>();
for (char element : input.toCharArray()) {
String_array.add(element);
}
HashSet<Character> charset = new HashSet<Character>();
int array_len = String_array.size();
System.out.println("\nLength of array = " + array_len);
if (String_array != null && array_len > 0) {
Iterator<Character> itr = String_array.iterator();
while (itr.hasNext()) {
Character c = (Character) itr.next();
if (charset.add(c)) {
} else {
itr.remove();
array_len--;
}
}
}
System.out.println("\nThe new string with no duplicates: \t");
for (int i = 0; i < array_len; i++) {
System.out.println(String_array.get(i).toString());
}
}
}
your can use this simple code and understand how to remove duplicates values from string.I think this is the simplest way to understand this problem.
class RemoveDup
{
static int l;
public String dup(String str)
{
l=str.length();
System.out.println("length"+l);
char[] c=str.toCharArray();
for(int i=0;i<l;i++)
{
for(int j=0;j<l;j++)
{
if(i!=j)
{
if(c[i]==c[j])
{
l--;
for(int k=j;k<l;k++)
{
c[k]=c[k+1];
}
j--;
}
}
}
}
System.out.println("after concatination lenght:"+l);
StringBuilder sd=new StringBuilder();
for(int i=0;i<l;i++)
{
sd.append(c[i]);
}
str=sd.toString();
return str;
}
public static void main(String[] ar)
{
RemoveDup obj=new RemoveDup();
Scanner sc=new Scanner(System.in);
String st,t;
System.out.println("enter name:");
st=sc.nextLine();
sc.close();
t=obj.dup(st);
System.out.println(t);
}
}
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package javaapplication26;
import java.util.*;
/**
*
* #author THENNARASU
*/
public class JavaApplication26 {
public static void main(String[] args) {
int i,j,k=0,count=0,m;
char a[]=new char[10];
char b[]=new char[10];
Scanner ob=new Scanner(System.in);
String str;
str=ob.next();
a=str.toCharArray();
int c=str.length();
for(j=0;j<c;j++)
{
for(i=0;i<j;i++)
{
if(a[i]==a[j])
{
count=1;
}
}
if(count==0)
{
b[k++]=a[i];
}
count=0;
}
for(m=0;b[m]!='\0';m++)
{
System.out.println(b[m]);
}
}
}
i wrote this program. Am using 2 char arrays instead. You can define the number of duplicate chars you want to eliminate from the original string and also shows the number of occurances of each character in the string.
public String removeMultipleOcuranceOfChar(String string, int numberOfChars){
char[] word1 = string.toCharArray();
char[] word2 = string.toCharArray();
int count=0;
StringBuilder builderNoDups = new StringBuilder();
StringBuilder builderDups = new StringBuilder();
for(char x: word1){
for(char y : word2){
if (x==y){
count++;
}//end if
}//end inner loop
System.out.println(x + " occurance: " + count );
if (count ==numberOfChars){
builderNoDups.append(x);
}else{
builderDups.append(x);
}//end if else
count = 0;
}//end outer loop
return String.format("Number of identical chars to be in or out of input string: "
+ "%d\nOriginal word: %s\nWith only %d identical chars: %s\n"
+ "without %d identical chars: %s",
numberOfChars,string,numberOfChars, builderNoDups.toString(),numberOfChars,builderDups.toString());
}
Try this simple solution for REMOVING DUPLICATE CHARACTERS/LETTERS FROM GIVEN STRING
import java.util.Scanner;
public class RemoveDuplicateLetters {
public static void main(String[] args) {
Scanner scn=new Scanner(System.in);
System.out.println("enter a String:");
String s=scn.nextLine();
String ans="";
while(s.length()>0)
{
char ch = s.charAt(0);
ans+= ch;
s = s.replace(ch+"",""); //Replacing all occurrence of the current character by a spaces
}
System.out.println("after removing all duplicate letters:"+ans);
}
}
In Java 8 we can do that using
private void removeduplicatecharactersfromstring() {
String myString = "aabcd eeffff ghjkjkl";
StringBuilder builder = new StringBuilder();
Arrays.asList(myString.split(" "))
.forEach(s -> {
builder.append(Stream.of(s.split(""))
.distinct().collect(Collectors.joining()).concat(" "));
});
System.out.println(builder); // abcd ef ghjkl
}

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