Program to check if the String is Null in Java

Program to check if the String is Null in Java

Last Updated : 27 Nov, 2024

In Java, checking if a string is null is essential for handling null-safe conditions and preventing runtime errors. To check if a string is null in Java, we can use the "==" operator that directly compares the string reference with null.

Example:

The below example demonstrates how to check if a given string is null using the == relational operator.

Java

// Java Program to check if
// a String is Null
class StringNull {

    // Method to check if the String is Null
    public static boolean isStringNull(String s)
    {

        // Compare the string with null
        // using == relational operator
        // and return the result
        if (s == null)
            return true;
        else
            return false;
    }

    // Driver code
    public static void main(String[] args)
    {
        // Test strings
        String s1 = "GeeksforGeeks";
        String s2 = null;

        System.out.println("Is string [" + s1
                           + "] null? "
                           + isStringNull(s1));
        System.out.println("Is string [" + s2
                           + "] null? "
                           + isStringNull(s2));
    }
}

Output

Is string [GeeksforGeeks] null? false
Is string [null] null? true

Explanation: The method isStringNull uses the == operator to check if the input string is null. It returns a boolean result, which is displayed for both null and non-null strings.

Program to check if the String is Null in Java

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