Java String contentEquals() Method

The String.contentEquals() method in Java is used to compare a string to a CharSequence or StringBuffer to determine if they have the same content.

Table of Contents

1. Introduction
2. contentEquals Method Syntax
3. Examples
   • Comparing with a StringBuffer
   • Comparing with a CharSequence
   • Real-World Use Case
4. Conclusion

Introduction

The String.contentEquals() method is a member of the String class in Java. It allows you to compare a string with another CharSequence or StringBuffer to check if they contain the same sequence of characters.

contentEquals() Method Syntax

There are two overloaded versions of the contentEquals method:

Comparing with a StringBuffer

public boolean contentEquals(StringBuffer sb)

• sb: The StringBuffer to compare with.

Comparing with a CharSequence

public boolean contentEquals(CharSequence cs)

• cs: The CharSequence to compare with.

Examples

Comparing with a StringBuffer

The contentEquals method can be used to compare a string with a StringBuffer.

Example

public class ContentEqualsStringBufferExample {
    public static void main(String[] args) {
        String str = "Hello, World!";
        StringBuffer sb = new StringBuffer("Hello, World!");

        boolean result = str.contentEquals(sb);
        System.out.println("String equals StringBuffer: " + result);
    }
}

Output:

String equals StringBuffer: true

Comparing with a CharSequence

The contentEquals method can be used to compare a string with a CharSequence.

Example

public class ContentEqualsCharSequenceExample {
    public static void main(String[] args) {
        String str = "Hello, World!";
        CharSequence cs = new StringBuilder("Hello, World!");

        boolean result = str.contentEquals(cs);
        System.out.println("String equals CharSequence: " + result);
    }
}

Output:

String equals CharSequence: true

Handling Edge Cases

Example: Comparing with Null

If the CharSequence or StringBuffer is null, the contentEquals method will return false.

public class ContentEqualsNullExample {
    public static void main(String[] args) {
        String str = "Hello, World!";
        StringBuffer sb = null;

        boolean result = str.contentEquals(sb);
        System.out.println("String equals null StringBuffer: " + result);
    }
}

Output:

String equals null StringBuffer: false

Example: Comparing Different Content

If the content of the String and CharSequence or StringBuffer are different, the contentEquals method will return false.

public class ContentEqualsDifferentExample {
    public static void main(String[] args) {
        String str = "Hello, World!";
        StringBuffer sb = new StringBuffer("Hello, Java!");

        boolean result = str.contentEquals(sb);
        System.out.println("String equals different StringBuffer: " + result);
    }
}

Output:

String equals different StringBuffer: false

Real-World Use Case

Example: Comparing User Input with Stored Data

One common use case for contentEquals is comparing user input with stored data that may be represented as a StringBuffer or StringBuilder.

public class ValidateUserInputExample {
    public static void main(String[] args) {
        String storedUsername = "User123";
        StringBuilder userInput = new StringBuilder("User123");

        if (storedUsername.contentEquals(userInput)) {
            System.out.println("Usernames match.");
        } else {
            System.out.println("Usernames do not match.");
        }
    }
}

Output:

Usernames match.

In this example, the contentEquals method is used to compare the stored username with the user input, which is represented as a StringBuilder.

Conclusion

The String.contentEquals() method in Java is a useful tool for comparing a string with a CharSequence or StringBuffer to check if they have the same content. It provides a straightforward way to perform content comparisons, which is useful for various applications such as validating user input and ensuring data consistency. By understanding and utilizing the contentEquals method, you can efficiently manage string comparisons in your Java programs.