I have a String value like this.
"Apple:1#Banana:2#Cake:3#Dog:4#Elephant:5"
a word : a number # a word : a number ...
and I want to separate the Strings into:
Apple
1
Banana
2
Cake
3
Dog
4
Elephant
5
...
However, I do not know how long the String is. Is there any way I can split each content connected with ":" and "#"?
Split on : or #:
String[] parts = str.split("[:#]");
You can replace all : symbol to # and split the string by #.
String str = "Apple:1#Banana:2#Cake:3#Dog:4#Elephant:5#";
String strrep = str.replaceAll(":","#");
String splitted[] = strrep.split("#");
for (String i : splitted){
System.out.println(i);
}
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter your input: ");
String input = scanner.nextLine();
Arrays.stream(input.split("[:#]")).forEach(System.out::println);
}
}
This is the code that gets input for example Apple:1#Banana:2#Cake:3#Dog:4#Elephant:5 and it will split the input by # and : and print them line by line.
The result shown on the console will be like
Enter your input:
Apple:1#Banana:2#Cake:3#Dog:4#Elephant:5
Apple
1
Banana
2
Cake
3
Dog
4
Elephant
5
Or you can do with a simpler way without streams
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.println("Enter your input: ");
String input = scanner.nextLine();
for (int i = 0; i < input.length();) {
int nextHashIdx = input.indexOf("#", i);
if (nextHashIdx == -1) nextHashIdx = input.length();
String strWithColon = input.substring(i, nextHashIdx);
String[] strs = strWithColon.split(":");
System.out.println(strs[0]);
System.out.println(strs[1]);
i = nextHashIdx + 1;
}
}
}
I have problem with my Java program. I am running the program on the console (CMD).
I would like, after I entered input, that the console stays on the same line (currently it goes to the next line automatically).
This is my current program:
int data[];
Scanner in = new Scanner(System.in);
data = new int[10];
System.out.println("Please Insert Numbers : ");
for(int i=0;i<5;i++)
{
data[i] = in.nextInt();
System.out.print("/t");
}
How can I return to the start of the line instead of going to the next?
Scanner in = new Scanner(System.in);
System.out.println("Please Insert Numbers Separated By Comma: ");
String input = in.nextLine();
input = input.replaceAll("\\s",""); //remove whitespaces
String[] numbers= input.split(","); //build string array using ',' as delimiter between numbers
int data[]= Arrays.asList(numbers).stream().mapToInt(Integer::parseInt).toArray(); //Available since Java8
Like Oscar Martinez said, you could read a string of numbers delimited by white space and build your integer array like this example (before parsing the string to int, I verify if the string can be converted to int or not using a regex ) :
import java.util.Arrays;
import java.util.Scanner;
public class Main {
public static void main(String[] args){
int data[];
Scanner in = new Scanner(System.in);
data = new int[10];
System.out.println("Please Insert Numbers : ");
String line = in.nextLine();
String[] stringsNumber = line.split("\\s");
for(int i=0;i<stringsNumber.length;i++){
if(stringsNumber[i].matches("^\\d+$") && i<10){// \\d is a regex to verify if s is a number
data[i]= Integer.parseInt(stringsNumber[i]);
}
}
System.out.println(Arrays.toString(data));
}
}
This program should input a dataset of names followed by the name "END". The program should print out the list of names in the dataset in reverse order from which they were entered. What I have works, but if I entered "Bob Joe Sally Sue" it prints "euS yllaS eoJ boB" insead of "Sue Sally Joe Bob". Help!?
import java.util.Scanner;
public class ReverseString {
public static void main(String args[]) {
String original, reverse = "";
Scanner kb = new Scanner(System.in);
System.out.println("Enter a list of names, followed by END:");
original = kb.nextLine();
int length = original.length();
while (!original.equalsIgnoreCase("END") ) {
for ( int i = length - 1; i >= 0 ; i-- )
reverse = reverse + original.charAt(i);
original = kb.next();
}
System.out.println("Reverse of entered string is: "+reverse);
}
}
I think that you need to use this simple algorithm. Actually you're not using the proper approach.
Take the whole string which contains all the names separated by spaces;
Split it using as a delimiter the space (use the method split)
After the split operation you will get back an array. Loop through it from the end (index:array.length-1) to the starter element (1) and save those elements in another string
public String reverseLine(String currLine) {
String[] splittedLine = currLine.split(" ");
StringBuilder builder = new StringBuilder("");
for(int i = splittedLine.length-1; i >= 1; i--) {
builder.append(splittedLine[i]).append(" ");
}
return builder.toString();
}
I've supposed that each lines contains all the names separated by spaces and at the end there is a string which is "END"
A quick way, storing the result in the StringBuilder:
StringBuilber reverse = new StringBuilder();
while (!original.equalsIgnoreCase("END")) {
reverse.append(new StringBuilder(original).reverse()).append(" ");
original = kb.next();
}
System.out.println("Reverse: " + reverse.reverse().toString());
Using the approach suggested in the comments above is very simple, and would look something like:
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
List<String> names = new ArrayList<>();
while (sc.hasNext())
{
String name = sc.next();
if (name.equals("END"))
{
break;
}
names.add(name);
}
Collections.reverse(names);
for (String name: names)
{
System.out.println(name);
}
System.out.println("END");
}
Let the Scanner extract the tokens for you, no need to do it yourself.
I am working on a program and I want to allow a user to enter multiple integers when prompted. I have tried to use a scanner but I found that it only stores the first integer entered by the user. For example:
Enter multiple integers: 1 3 5
The scanner will only get the first integer 1. Is it possible to get all 3 different integers from one line and be able to use them later? These integers are the positions of data in a linked list I need to manipulate based on the users input. I cannot post my source code, but I wanted to know if this is possible.
I use it all the time on hackerrank/leetcode
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String lines = br.readLine();
String[] strs = lines.trim().split("\\s+");
for (int i = 0; i < strs.length; i++) {
a[i] = Integer.parseInt(strs[i]);
}
Try this
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
while (in.hasNext()) {
if (in.hasNextInt())
System.out.println(in.nextInt());
else
in.next();
}
}
By default, Scanner uses the delimiter pattern "\p{javaWhitespace}+" which matches at least one white space as delimiter. you don't have to do anything special.
If you want to match either whitespace(1 or more) or a comma, replace the Scanner invocation with this
Scanner in = new Scanner(System.in).useDelimiter("[,\\s+]");
You want to take the numbers in as a String and then use String.split(" ") to get the 3 numbers.
String input = scanner.nextLine(); // get the entire line after the prompt
String[] numbers = input.split(" "); // split by spaces
Each index of the array will hold a String representation of the numbers which can be made to be ints by Integer.parseInt()
Scanner has a method called hasNext():
Scanner scanner = new Scanner(System.in);
while(scanner.hasNext())
{
System.out.println(scanner.nextInt());
}
If you know how much integers you will get, then you can use nextInt() method
For example
Scanner sc = new Scanner(System.in);
int[] integers = new int[3];
for(int i = 0; i < 3; i++)
{
integers[i] = sc.nextInt();
}
Java 8
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
int arr[] = Arrays.stream(in.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
Here is how you would use the Scanner to process as many integers as the user would like to input and put all values into an array. However, you should only use this if you do not know how many integers the user will input. If you do know, you should simply use Scanner.nextInt() the number of times you would like to get an integer.
import java.util.Scanner; // imports class so we can use Scanner object
public class Test
{
public static void main( String[] args )
{
Scanner keyboard = new Scanner( System.in );
System.out.print("Enter numbers: ");
// This inputs the numbers and stores as one whole string value
// (e.g. if user entered 1 2 3, input = "1 2 3").
String input = keyboard.nextLine();
// This splits up the string every at every space and stores these
// values in an array called numbersStr. (e.g. if the input variable is
// "1 2 3", numbersStr would be {"1", "2", "3"} )
String[] numbersStr = input.split(" ");
// This makes an int[] array the same length as our string array
// called numbers. This is how we will store each number as an integer
// instead of a string when we have the values.
int[] numbers = new int[ numbersStr.length ];
// Starts a for loop which iterates through the whole array of the
// numbers as strings.
for ( int i = 0; i < numbersStr.length; i++ )
{
// Turns every value in the numbersStr array into an integer
// and puts it into the numbers array.
numbers[i] = Integer.parseInt( numbersStr[i] );
// OPTIONAL: Prints out each value in the numbers array.
System.out.print( numbers[i] + ", " );
}
System.out.println();
}
}
There is more than one way to do that but simple one is using String.split(" ")
this is a method of String class that separate words by a spacial character(s) like " " (space)
All we need to do is save this word in an Array of Strings.
Warning : you have to use scan.nextLine(); other ways its not going to work(Do not use scan.next();
String user_input = scan.nextLine();
String[] stringsArray = user_input.split(" ");
now we need to convert these strings to Integers. create a for loop and convert every single index of stringArray :
for (int i = 0; i < stringsArray.length; i++) {
int x = Integer.parseInt(stringsArray[i]);
// Do what you want to do with these int value here
}
Best way is converting the whole stringArray to an intArray :
int[] intArray = new int[stringsArray.length];
for (int i = 0; i < stringsArray.length; i++) {
intArray[i] = Integer.parseInt(stringsArray[i]);
}
now do any proses you want like print or sum or... on intArray
The whole code will be like this :
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
String user_input = scan.nextLine();
String[] stringsArray = user_input.split(" ");
int[] intArray = new int[stringsArray.length];
for (int i = 0; i < stringsArray.length; i++) {
intArray[i] = Integer.parseInt(stringsArray[i]);
}
}
}
This works fine ....
int a = nextInt();
int b = nextInt();
int c = nextInt();
Or you can read them in a loop
Using this on many coding sites:
CASE 1: WHEN NUMBER OF INTEGERS IN EACH LINE IS GIVEN
Suppose you are given 3 test cases with each line of 4 integer inputs separated by spaces 1 2 3 4, 5 6 7 8 , 1 1 2 2
int t=3,i;
int a[]=new int[4];
Scanner scanner = new Scanner(System.in);
while(t>0)
{
for(i=0; i<4; i++){
a[i]=scanner.nextInt();
System.out.println(a[i]);
}
//USE THIS ARRAY A[] OF 4 Separated Integers Values for solving your problem
t--;
}
CASE 2: WHEN NUMBER OF INTEGERS in each line is NOT GIVEN
Scanner scanner = new Scanner(System.in);
String lines=scanner.nextLine();
String[] strs = lines.trim().split("\\s+");
Note that you need to trim() first: trim().split("\\s+") - otherwise, e.g. splitting a b c will emit two empty strings first
int n=strs.length; //Calculating length gives number of integers
int a[]=new int[n];
for (int i=0; i<n; i++)
{
a[i] = Integer.parseInt(strs[i]); //Converting String_Integer to Integer
System.out.println(a[i]);
}
created this code specially for the Hacker earth exam
Scanner values = new Scanner(System.in); //initialize scanner
int[] arr = new int[6]; //initialize array
for (int i = 0; i < arr.length; i++) {
arr[i] = (values.hasNext() == true ? values.nextInt():null);
// it will read the next input value
}
/* user enter = 1 2 3 4 5
arr[1]= 1
arr[2]= 2
and soo on
*/
It's working with this code:
Scanner input = new Scanner(System.in);
System.out.println("Enter Name : ");
String name = input.next().toString();
System.out.println("Enter Phone # : ");
String phone = input.next().toString();
A simple solution can be to consider the input as an array.
Scanner sc = new Scanner(System.in);
int n = sc.nextInt(); //declare number of integers you will take as input
int[] arr = new int[n]; //declare array
for(int i=0; i<arr.length; i++){
arr[i] = sc.nextInt(); //take values
}
You're probably looking for String.split(String regex). Use " " for your regex. This will give you an array of strings that you can parse individually into ints.
Better get the whole line as a string and then use StringTokenizer to get the numbers (using space as delimiter ) and then parse them as integers . This will work for n number of integers in a line .
Scanner sc = new Scanner(System.in);
List<Integer> l = new LinkedList<>(); // use linkedlist to save order of insertion
StringTokenizer st = new StringTokenizer(sc.nextLine(), " "); // whitespace is the delimiter to create tokens
while(st.hasMoreTokens()) // iterate until no more tokens
{
l.add(Integer.parseInt(st.nextToken())); // parse each token to integer and add to linkedlist
}
Using BufferedReader -
StringTokenizer st = new StringTokenizer(buf.readLine());
while(st.hasMoreTokens())
{
arr[i++] = Integer.parseInt(st.nextToken());
}
When we want to take Integer as inputs
For just 3 inputs as in your case:
import java.util.Scanner;
Scanner scan = new Scanner(System.in);
int a,b,c;
a = scan.nextInt();
b = scan.nextInt();
c = scan.nextInt();
For more number of inputs we can use a loop:
import java.util.Scanner;
Scanner scan = new Scanner(System.in);
int a[] = new int[n]; //where n is the number of inputs
for(int i=0;i<n;i++){
a[i] = scan.nextInt();
}
This method only requires users to enter the "return" key once after they have finished entering numbers:
It also skips special characters so that the final array will only contains integers
ArrayList<Integer> nums = new ArrayList<>();
// User input
Scanner sc = new Scanner(System.in);
String n = sc.nextLine();
if (!n.isEmpty()) {
String[] str = n.split(" ");
for (String s : str) {
try {
nums.add(Integer.valueOf(s));
} catch (NumberFormatException e) {
System.out.println(s + " cannot be converted to Integer, skipping...");
}
}
}
//Get user input as a 1 2 3 4 5 6 .... and then some of the even or odd number like as 2+4 = 6 for even number
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int evenSum = 0;
int oddSum = 0;
while (n > 0) {
int last = n % 10;
if (last % 2 == 0) {
evenSum += last;
} else {
oddSum += last;
}
n = n / 10;
}
System.out.println(evenSum + " " + oddSum);
}
}
if ur getting nzec error, try this:
try{
//your code
}
catch(Exception e){
return;
}
i know it's old discuss :) i tested below code it's worked
`String day = "";
day = sc.next();
days[i] = Integer.parseInt(day);`
I need to get a number of words from user, and then output a final word which is formed by the concatenation of the last letters of the words that the user has input.
Here is the code. But how do I bring these letters from the loop and concatenate them?
import java.util.Scanner;
public class newWord {
public static void main(String args[]) {
System.out.println("How many words are you going to enter?");
Scanner num = new Scanner(System.in);
int number = num.nextInt();
System.out.println("Please Enter the "+number+" words:");
for(int n=1;n<=number;n++)
{
Scanner words = new Scanner(System.in);
String thisword = words.nextLine();
char str2 = thisword.charAt(thisword.length()-1);
System.out.println(str2);
}
}
}
Hints only ... since this is obviously a learning exercise of some kind.
But how do I bring these letters from the loop and concatenate them?
You don't. You concatenate them within the loop.
String concatenation can be done using the String + operator or StringBuilder.
The rest is up to you. (Please ignore the dingbats who posted complete solutions and work it out for yourself. It will do you good!)
You can use StringBuilder class to concatenate latest characters in strings with append method.
I believe (correct me if I'm wrong) you are asking to take the last letter of each word and make that into one final word. All you need to do is take each of the final letters and add them to a String to hold them all. After the entire for loop, the variable appended should be your requested word.
public static void main(String args[]) {
System.out.println("How many words are you going to enter?");
Scanner num = new Scanner(System.in);
int number = num.nextInt();
System.out.println("Please Enter the "+number+" words:");
String appended = ""; // Added this
for(int n=1;n<=number;n++)
{
Scanner words = new Scanner(System.in);
String thisword = words.nextLine();
char str2 = thisword.charAt(thisword.length()-1);
appended +=str2; // Added this
System.out.println(str2);
}
}
Just you miss things to keep final value in a place and finally print
public static void main(String args[]) {
System.out.println("How many words are you going to enter?");
Scanner num = new Scanner(System.in);
int number = num.nextInt();
System.out.println("Please Enter the "+number+" words:");
StringBuffer sb = new StringBuffer();
for(int n=1;n<=number;n++)
{
Scanner words = new Scanner(System.in);
String thisword = words.nextLine();
char str2 = thisword.charAt(thisword.length()-1);
sb.append(str2);
}
System.out.println(sb.toString());
}
go through StringBuilder and StringBuffer classes you will get your answer..