how to count the spaces in a java string?

Question

I need to count the number of spaces in my string but my code gives me a wrong number when i run it, what is wrong?

int count=0;
String arr[]=s.split("\t");
println("Number of spaces are: "+arr.length);
count++;

"\t" is a tab String, not a space. The last I checked, a space String looked like this: " ". — Hovercraft Full Of Eels, Mar 11 '12 at 14:29

score 37 · Answer 1 · edited May 25 '23 at 17:30

s.length() - s.replaceAll(" ", "").length() returns you number of spaces.

There are more ways. For example:

int spaceCount = 0;
for (char c : str.toCharArray()) {
    if (c == ' ') {
         spaceCount++;
    }
}

In your case you tried to split the string using \t, i.e. TAB. You will get the right result if you use " " instead. Using \s may be confusing since it matches all whitespaces, i.e. regular spaces and TABs.

score 24 · Answer 2 · edited Jun 15 '21 at 17:43

24

Here is a different way of looking at it, and it's a simple one-liner:

int spaces = s.replaceAll("[^ ]", "").length();

This works by effectively removing all non-spaces then taking the length of what’s left (the spaces).

You might want to add a null check:

int spaces = s == null ? 0 : s.replaceAll("[^ ]", "").length();

Java 8 update

You can use a stream too:

long spaces = s.chars().filter(c -> c == (int)' ').count();

edited Jun 15 '21 at 17:43

ToWy

23
7

answered Mar 11 '12 at 14:37

Bohemian

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3

variable spaces's type should be long not int. – aolphn Sep 25 '18 at 02:42

score 8 · Answer 3 · answered Mar 11 '12 at 15:17

Fastest way to do this would be:

int count = 0;
for(int i = 0; i < str.length(); i++) {
     if(Character.isWhitespace(str.charAt(i))) count++;
}

This would catch all characters that are considered whitespace.

Regex solutions require compiling regex and excecuting it - with a lot of overhead. Getting character array requires allocation. Iterating over byte array would be faster, but only if you are sure that your characters are ASCII.

chooban · Answer 4 · 2012-03-11T14:39:41.010

5

\t will match tabs, rather than spaces and should also be referred to with a double slash: \\t. You could call s.split( " " ) but that wouldn't count consecutive spaces. By that I mean...

String bar = " ba jfjf jjj j   ";
String[] split = bar.split( " " );
System.out.println( split.length ); // Returns 5

So, despite the fact there are seven space characters, there are only five blocks of space. It depends which you're trying to count, I guess.

Commons Lang is your friend for this one.

int count = StringUtils.countMatches( inputString, " " );

edited Mar 11 '12 at 14:39

answered Mar 11 '12 at 14:31

chooban

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You're wrong about `s.split(" ")` not counting consecutive spaces - it does. – Bohemian Mar 11 '12 at 14:36

Donald Raab · Answer 5 · 2019-03-19T01:36:56.483

4

If you use Java 8, the following should work:

long count = "0 1 2 3 4.".chars().filter(Character::isWhitespace).count();

This will also work in Java 8 using Eclipse Collections:

int count = Strings.asChars("0 1 2 3 4.").count(Character::isWhitespace);

Note: I am a committer for Eclipse Collections.

edited Mar 19 '19 at 01:36

answered Jun 23 '17 at 19:06

Donald Raab

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score 2 · Answer 6 · answered Mar 11 '12 at 14:29

2

Your code will count the number of tabs and not the number of spaces. Also, the number of tabs will be one less than arr.length.

answered Mar 11 '12 at 14:29

nikhil500

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score 2 · Answer 7 · answered Mar 11 '12 at 14:42

2

Another way using regular expressions

int length = text.replaceAll("[^ ]", "").length();

answered Mar 11 '12 at 14:42

Peter Lawrey

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score 1 · Answer 8 · edited Apr 14 '18 at 00:08

1

please check the following code, it can help

 public class CountSpace {

    public static void main(String[] args) {

        String word = "S N PRASAD RAO";
        String data[];int k=0;
        data=word.split("");
        for(int i=0;i<data.length;i++){
            if(data[i].equals(" ")){
                k++;
            }

        }
        System.out.println(k);

    }
}

edited Apr 14 '18 at 00:08

Ahmad Al-Kurdi

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answered Feb 08 '13 at 21:37

S N Prasad Rao

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score 1 · Answer 9 · answered May 23 '18 at 07:47

1

The simple and fastest way to count spaces

 String fav="foo hello me hi";
for( int i=0; i<fav.length(); i++ ) {
        if(fav.charAt(i) == ' ' ) {
            counter++;
        }
    }

answered May 23 '18 at 07:47

Syed Danish Haider

1,334
11
15

score 1 · Answer 10 · answered Mar 11 '12 at 14:30

1

The code you provided would print the number of tabs, not the number of spaces. The below function should count the number of whitespace characters in a given string.

int countSpaces(String string) {
    int spaces = 0;
    for(int i = 0; i < string.length(); i++) {
        spaces += (Character.isWhitespace(string.charAt(i))) ? 1 : 0;
    }
    return spaces;
}

answered Mar 11 '12 at 14:30

2

The ternary operator really isn't needed here, it would be clearer to just have a single if and ignore the case when the `char` isn't whitespace. – Jeffrey Mar 11 '12 at 14:55

score 1 · Answer 11 · answered Mar 11 '12 at 15:11

A solution using java.util.regex.Pattern / java.util.regex.Matcher

String test = "foo bar baz ";
Pattern pattern = Pattern.compile(" ");
Matcher matcher = pattern.matcher(test);
int count = 0;
while (matcher.find()) {
    count++;
}
System.out.println(count);

score 0 · Answer 12 · answered Jul 17 '15 at 21:06

0

I just had to do something similar to this and this is what I used:

String string = stringValue;
String[] stringArray = string.split("\\s+");
int length = stringArray.length;
System.out.println("The number of parts is: " + length);

answered Jul 17 '15 at 21:06

James Drinkard

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score 0 · Answer 13 · answered Feb 16 '17 at 12:21

public static void main(String[] args) {
    String str = "Honey   dfd    tEch Solution";
    String[] arr = str.split(" ");
    System.out.println(arr.length);
    int count = 0;
    for (int i = 0; i < arr.length; i++) {
        if (!arr[i].trim().isEmpty()) {
            System.out.println(arr[i]);
            count++;
        }
    }
    System.out.println(count);
}

HSN · Answer 14 · 2017-06-15T07:27:26.163

0

public static void main(String[] args) {  
Scanner input= new Scanner(System.in);`

String data=input.nextLine();
int cnt=0;
System.out.println(data);
for(int i=0;i<data.length()-1;i++)
{if(data.charAt(i)==' ')
    {
        cnt++;
    }
}

System.out.println("Total number of Spaces in a given String are " +cnt);
}

edited Jun 15 '17 at 07:27

answered Jun 14 '17 at 13:02

HSN

1
1

score 0 · Answer 15 · edited Apr 13 '18 at 22:16

This program will definitely help you.

class SpaceCount
{

    public static int spaceCount(String s)
    { int a=0;
        char ch[]= new char[s.length()];
        for(int i = 0; i < s.length(); i++) 

        {  ch[i]= s.charAt(i);
            if( ch[i]==' ' )
            a++;
                }   
        return a;
    }


    public static void main(String... s)
    {
        int m = spaceCount("Hello I am a Java Developer");
        System.out.println("The number of words in the String are :  "+m);

    }
}

score 0 · Answer 16 · answered May 06 '18 at 05:37

The most precise and exact plus fastest way to that is :

String Name="Infinity War is a good movie";

    int count =0;

    for(int i=0;i<Name.length();i++){
    if(Character.isWhitespace(Name.charAt(i))){
    count+=1;
        }
    }

    System.out.println(count);

score 0 · Answer 17 · answered Jun 25 '21 at 08:42

import java.util.Scanner;
import java.io.*;

public class Main {
       public static void main(String args[]) {
  
          Scanner sc = new Scanner(System.in).useDelimiter("\n");
          String str = sc.next();
          int spaceCount=0;
          str = str.toLowerCase();    
        
          for(int i = 0; i < str.length(); i++) {
              if(str.charAt(i)==' '){
                  spaceCount++;
              }
          }
          System.out.println("Number of spaces: "+ spaceCount);
     }
}

how to count the spaces in a java string?

17 Answers17

Java 8 update

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