How can I find whitespace in a String?

Question

How can I check to see if a String contains a whitespace character, an empty space or \" \". If possible, please provide a Java example.

For example: String

Answer 1

Check whether a String contains at least one white space character:

public static boolean containsWhiteSpace(final String testCode){
    if(testCode != null){
        for(int i = 0; i < testCode.length(); i++){
            if(Character.isWhitespace(testCode.charAt(i))){
                return true;
            }
        }
    }
    return false;
}

Reference:

• Character.isWhitespace(char)

---

Using the Guava library, it's much simpler:

return CharMatcher.WHITESPACE.matchesAnyOf(testCode);

CharMatcher.WHITESPACE is also a lot more thorough when it comes to Unicode support.

Answer 2

Use org.apache.commons.lang.StringUtils.

1. to search for whitespaces

boolean withWhiteSpace = StringUtils.contains("my name", " ");

2. To delete all whitespaces in a string

StringUtils.deleteWhitespace(null) = null StringUtils.deleteWhitespace("") = "" StringUtils.deleteWhitespace("abc") = "abc" StringUtils.deleteWhitespace(" ab c ") = "abc"

Answer 3

I purpose to you a very simple method who use String.contains:

public static boolean containWhitespace(String value) {
    return value.contains(" ");
}

A little usage example:

public static void main(String[] args) {
    System.out.println(containWhitespace("i love potatoes"));
    System.out.println(containWhitespace("butihatewhitespaces"));
}

Output:

true
false

Answer 4

You can basically do this

if(s.charAt(i)==32){
   return true;
}

You must write boolean method.Whitespace char is 32.

Answer 5

You can use charAt() function to find out spaces in string.

 public class Test {
  public static void main(String args[]) {
   String fav="Hi Testing  12 3";
   int counter=0;
   for( int i=0; i<fav.length(); i++ ) {
    if(fav.charAt(i) == ' ' ) {
     counter++;
      }
     }
    System.out.println("Number of spaces "+ counter);
    //This will print Number of spaces 4
   }
  }

Answer 6

For checking if a string contains whitespace use a Matcher and call it's find method.

Pattern pattern = Pattern.compile("\\s");
Matcher matcher = pattern.matcher(s);
boolean found = matcher.find();

If you want to check if it only consists of whitespace then you can use String.matches:

boolean isWhitespace = s.matches("^\\s*$");