Jul 23, 2023 Author - Sai gowtham

How to check if a given string is number in Java

java1min read

To check whether a given string is number or not, we can use the string.chars().allMatch() method where it returns true if a string is number else it returns false.

Here is an example:

public class Main
{
    public static void main(String[] args) {

            String myString = "9291";
            boolean isNumeric = myString.chars().allMatch( Character::isDigit );
            if(isNumeric)
            System.out.println(myString + " is a number");
          else
            System.out.println(myString + " is not a number");
    }
}

Output:

9291 is a number

False case

public class Main
{
    public static void main(String[] args) {

            String myString = "hello fashion";
            boolean isNumeric = myString.chars().allMatch( Character::isDigit );
            if(isNumeric)
            System.out.println(myString + " is a number");
          else
            System.out.println(myString + " is not a number");
    }
}