I am trying to terminate my code when "END" is input into the console, however my code wont play fair and I can't seem to see where it is going wrong, btw I haven't learnt how to debug as of yet so this has largely got to do with why i can't figure it out. please do help if you can.
import java.util.*;
class Main
{
public static void main(String args[])
{
int j = 0;
while (j++ <= 3) {
// Create Scanner object to take input from command prompt
Scanner s=new Scanner(System.in);
// Take input from the user and store it in st
String st = "";
while (!st.equals("END")) {
{
st=s.nextLine();
// Initialize the variable count to 0
int count=0;
// Convert String st to char array
char[] c=st.toCharArray();
// Loop till end of string
for(int i=0;i<st.length();i++)
// If character at index 'i' is not a space, then increment count
if(c[i]!=' ') count++;
// Print no.of spaces
System.out.printf("[%4d] spaces in ", +(st.length()-count));
// Print no.of spaces
System.out.println('"' + st + '"');
}
j++;
}
}
}
Since you have while (j++ <= 3) { ... } your program will end if you enter "END" two times.
Because you have two while loops nested. You input "END" in the second while loop and after that the second loop ends that's correct. But as you see, after it ends it will start the first loop which is while (j++ <= 3) { and in this while loop it waits for an input from user 3 times, which corresponds to Scanner s=new Scanner(System.in);, therefore it is normal for your program not to exit. If you want your program to finish after some input you may want to use System.exit(-1); command. I've added code according to your comments.
import java.util.*;
class Main {
public static void main(String args[]) {
int j = 0;
while (j++ <= 3) {
// Create Scanner object to take input from command prompt
Scanner s = new Scanner(System.in);
// Take input from the user and store it in st
String st = s.nextLine();
if (!st.equals("END")) {
// Initialize the variable count to 0
int count = 0;
// Convert String st to char array
char[] c = st.toCharArray();
// Loop till end of string
for (int i = 0; i < st.length(); i++)
// If character at index 'i' is not a space, then increment count
{
if (c[i] != ' ') {
count++;
}
}
// Print no.of spaces
System.out.printf("[%4d] spaces in ", +(st.length() - count));
// Print no.of spaces
System.out.println('"' + st + '"');
} else {
System.exit(-1);
}
}
}
}
I have just add an if condition without using loop.
public static void main(String args[]) {
int j = 0;
while (j++ <= 3) {
// Create Scanner object to take input from command prompt
Scanner s = new Scanner(System.in);
// Take input from the user and store it in st
String st = "";
st = s.nextLine();
if (st.equalsIgnoreCase("END")) {
j = 5;
}
// Initialize the variable count to 0
int count = 0;
// Convert String st to char array
char[] c = st.toCharArray();
// Loop till end of string
for (int i = 0; i < st.length(); i++) // If character at index 'i' is not a space, then increment count
{
if (c[i] != ' ') {
count++;
}
}
// Print no.of spaces
System.out.printf("[%4d] spaces in ", +(st.length() - count));
// Print no.of spaces
System.out.println('"' + st + '"');
j++;
}
}
What I do basically when I get the input end I just change the value of j to 5 so that the first loop will be terminated. and stop taking inpu.
Do you want this type of solution or you want you need to take input 3 times?
Related
I am trying to reduce the string array by using a for a loop. This is an example I tried to do
User string input: Calculus
User input:5
output: CalcuCalcCalCaC
I have turned the string to a char array but the issue presents itself when trying to print them out multiple times. It only prints once and has the right starting output.
input string: Oregon
input number: 4
output: Oreg
I notice my for loop says that it is not looping when I hover over it on the IDE that I downloaded from JetBrains.
I tried different combinations of decrementing and incrementing but could not get that "for statement is not looping". Other than that I have tried different ways to do something in the for loop but I don't think anything needs to be done for now if the for loop is not looping then, right?
So my question is, how to reduce a string or char array and print the decrement value over and over again?
Here is my code so far for it.
public String wordDown(String userString, int userNum)
{
String stringModded = userString.substring(0, userNum);
char[] charArray = stringModded.toCharArray();
char repeat = ' ';
for(int i = 0; i<userNum; ++i)
{
repeat = (char) (repeat +charArray[i]);
charArray[i] = repeat;
for(int j = 1; i > charArray.length; ++j)
{
String modWord = String.valueOf(charArray[i + 1]);
return modWord;
}
}
return null;
}
public static void main(String[] args)
{
int userNumber;
String userString;
RandomArrayFunctionalities ranMethod = new RandomArrayFunctionalities();
Scanner in = new Scanner(System.in);
System.out.println("\nEnter a word:");
userString = in.next();
System.out.println("\nEnter a number within the word scope that you just enter:");
userNumber = in.nextInt();
System.out.println(ranMethod.wordDown(userString, userNumber));
}
You do not need to modify the original array. Use a StringBuilder to concatenate the successive parts of the word. Use the String.substring(int,int) method to pull out those parts. The example that follows uses a decrementing index to generate the successively smaller substrings.
public String wordDown(String word, int userNum) {
StringBuilder sb = new StringBuilder();
for (int length = userNum ; length > 0 ; --length) {
sb.append(word.substring(0, length));
}
return sb.toString();
}
I think you are over complicating things, you don't need a char array at all and you only need a single loop, and a single return statement:
public String wordDown(String userString, int userNum) {
String finalString = "";
for (int i = 0; i < userNum; ++i) {
finalString = finalString + userString.substring(0, userNum - i);
}
return finalString;
}
Simply loop up to the inputted number and substring from 0 to inputtedNumber - loopCounter and append the result to the previously held String value.
Example Run:
Enter a word:
Calculus
Enter a number within the word scope that you just enter:
5
CalcuCalcCalCaC
Sidenote:
Technically you would want to use StringBuilder instead of appending String in a loop, but that is probably out of the scope of this question. Here is that version just for reference:
public String wordDown(String userString, int userNum) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < userNum; ++i) {
sb.append(userString.substring(0, userNum - i));
}
return sb.toString();
}
Write a program that takes a string input from the user and then outputs the first character, then the first two, then the first three, etc until it prints the entire word. After going down to one letter, print the opposite back up to the full word.
I've gotten the first part done.
Scanner word = new Scanner(System.in);
System.out.println("Enter a word.");
String thing = word.next();
String rest = "";
for(int i=0;i< thing.length();i++){
String w = thing.substring(i,i+1);
rest += w;
System.out.println(rest);
}
This is what it should look like.
C
Co
Com
Comp
Compu
Comput
Compute
Computer
Computer
Compute
Comput
Compu
Comp
Com
Co
C
Strings in Java are indexed starting from 0, so the last character is indexed at length-1.
To iterate from the last character down to the first, the for loop would be for(int i = thing.length () - 1; i >= 0; i--).
Alternatively, recursion would be a simpler solution considering you already obtained the strings that should be printed in reverse.
static void f (String str, int n) {
if (n > str.length ()) return;
String temp = str.substring (0, n); // obtain the string
System.out.println (temp); // print
f (str, n + 1); // go to next substring
System.out.println (temp); // print after returning from the last obtainable substring
}
The function can now be called via f(thing, n);
You can try to implement two arrays, in the first you must split the String entered from the Scanner and in the second you must store the generated aux variable in each iteration of the first array, To finish you must iterate the second array in reverse.
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a word: ");
String word = sc.next();
String[] array = word.split("");
int length = array.length;
String[] auxArray = new String[length];
String aux = "";
for (int i = 0; i < length; i++) {
aux += array[i];
auxArray[i] = aux;
System.out.println(aux);
}
for (int i = length - 1; i >= 0; i--) {
System.out.println(auxArray[i]);
}
}
I understand how to count the occurrences of specific characters in a string. What I am struggling is printing "The specific character is at location x, y, z". If I place the text within the loop that tests for location, the text is printed multiple times. I do not want that to happen.
There are other constraints as well. I must keep the program basic, and I am limited to using the charAt() and string.lenghth() functions. The program should only exit when the user enters "-1". When the user enters the string, the program should read through the characters, output the location of the specific characters, and then prompt the user to enter a new string. I am also struggling with allowing the user to enter a new string and running the loop again.
Here is the code I have so far
import java.util.Scanner;
public class GimmeAW {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter the Line\nEntering -1 exits the program")
String aLine;
aLine = input.nextLine();
char one = aLine.charAt(0);
char two = aLine.charAt(1);
if (one == '-' && two == '1') {
System.out.println("System Exit");
System.exit(1);
}
for (int i = 0; i < aLine.length(); i++) {
if (aLine.charAt(i) == 'w' || aLine.charAt(i) == 't') {
int location = i;
System.out.print(" " + i);
}
}
}
To avoid printing the msg multiple times, just keep the msg outside of the counting loop and print it once for each character ...
char[] ch = {'w', 't'}; // characters to count
int l = aLine.length();
for(int i = 0; i < ch.length; i++) {
System.out.print("The character " + ch[i] + " is at locations ");
// searching
for(int j = 0; j < l; j++) {
if(aLine.charAt(j) == ch[i]) {
System.out.print(j + " ");
}
}
System.out.println();
}
And you can put all the code you want to repeat inside a do-while loop and run it until the user wants to.
String choice = "yes";
do {
// code
// want to repeat ??
choice = in.nextLine();
} while(choice.equals("yes"));
I have the basics, but I need to make it so that my program will work without printing the unused letters of the alphabet at the end, say my sentence is "dog" I would want the output to be: D-1
O-1
G-1, instead of A-0 B-0 D-1, and so on. Thanks for any help provided, it is greatly appreciated.
what I have so far is:
package as10;
import java.util.*;
public class as
{
private static void countLetters(String sentenceString)
{
int[] array = new int[26];
sentenceString = sentenceString.toUpperCase();
for (int i = 0; i < sentenceString.length(); ++i)
{
if (sentenceString.charAt(i) >= 'A' && sentenceString.charAt(i) <= 'Z')
{
++array[sentenceString.charAt(i) - 'A'];
}
}
for (int i = 0; i < 26; ++i)
{
System.out.println((char) ('A' + i) + " - " + array[i]);
}
}
public static void main(String[] args)
{
Scanner kbd = new Scanner(System.in);
String letterString;
while (true)
{
System.out.println("Enter a line of text: ");
letterString = kbd.nextLine();
System.out.println("Letter Frequencies: ");
countLetters(letterString);
break;
}
kbd.close();
}
}
so, basically, you want to opt out all chars if counter is 0.
In other words, you will need an if statement around print line and only perform system output if relevant array value is non-zero.
Above statement is in pure English. It is again your assignment to convert that sentence into java, as I refuse to do your homework on your behalf.
Does it sound fair ? :)
The code works the first time through. But after that, the output doesnt work.
The main goal of this is to create an infinite loop, of asking a user for a phrase, then a letter. Then, to output the number of occurences of the letter in the phrase.
Also - - how would i go about breaking this loop by entering a word?
Scanner in = new Scanner(System.in);
for (;;) {
System.out.println("Enter a word/phrase");
String sentence = in.nextLine();
int times = 0;
System.out.println("Enter a character.");
String letter = in.next();
for (int i = 0; i < sentence.length(); i++) {
char lc = letter.charAt(0);
char sc = sentence.charAt(i);
if (lc == sc) {
times++;
}
}
System.out.print("The character appeared:" + times + " times.");
}
Remove the for loop and replace it with a while.
The while loop should check for a phrase and it will drop out automatically when the phrase is met.
So something like
while (!phraseToCheckFor){
// your code
}
This sounds like homework so I won't post all the code but this should be enough to get you started.
If you need an infinite loop, just do this:
for(;;) { //or while(true) {
//insert code here
}
You can break the loop by using the break statement, for example like this:
for(;;) {
String s = in.nextLine();
if(s.isEmpty()) {
break; //loop terminates here
}
System.out.println(s + " isn't empty.");
}
In order for your program to run correctly, you need to consume the last new line character. You can do this by adding a call to nextLine.
Working example,
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
for (;;) {
System.out.println("Enter a word/phrase");
String sentence = in.nextLine();
if (sentence.trim().equals("quit")) {
break;
}
int times = 0;
System.out.println("Enter a character.");
String letter = in.next();
for (int i = 0; i < sentence.length(); i++) {
char lc = letter.charAt(0);
char sc = sentence.charAt(i);
if (lc == sc) {
times++;
}
}
System.out.println("The character appeared:" + times + " times.");
in.nextLine();//consume the last new line
}
}