Java String endsWith() Method

What You’ll Learn

The endsWith() method answers a focused question: “Does this string end with that suffix?” It returns true or false, which makes it ideal for file extensions, URL paths, and suffix-based validation.

Definition and Usage

In Java, endsWith(String suffix) is defined on java.lang.String. It compares the trailing characters of the calling string with the suffix argument. If "Hello, World!" ends with "World!", the method returns true.

Unlike contains(), which searches anywhere in the text, endsWith() only cares about the final characters. Unlike startsWith(), it checks the suffix rather than the prefix.

📝 Syntax

The endsWith() method is declared in the String class:

public boolean endsWith(String suffix)

Parameters

• suffix — the ending substring to test. Must not be null.

Return Value

Returns true if the string ends with suffix; otherwise false.

Exceptions

Throws NullPointerException if suffix is null.

Examples Gallery

These programs run in Java 8+. They show a matching suffix, a failed check, file extension validation, case-insensitive matching, and comparison with related methods.

public class EndsWithExample {
    public static void main(String[] args) {
        String text = "Hello, World!";

        boolean endsWithWorld = text.endsWith("World!");

        System.out.println("Ends with 'World!'? " + endsWithWorld);
    }
}

Ends with 'World!'? true

public class NotFoundDemo {
    public static void main(String[] args) {
        String text = "Hello, World!";

        System.out.println("Ends with 'Java'?  " + text.endsWith("Java"));
        System.out.println("Ends with 'Hello'? " + text.endsWith("Hello"));
    }
}

Ends with 'Java'?  false
Ends with 'Hello'? false

public class FileExtensionCheck {
    public static void main(String[] args) {
        String file1 = "Main.java";
        String file2 = "readme.txt";

        System.out.println(file1 + " is Java? " + file1.endsWith(".java"));
        System.out.println(file2 + " is Java? " + file2.endsWith(".java"));
    }
}

Main.java is Java? true
readme.txt is Java? false

public class IgnoreCaseEndsWith {
    public static boolean endsWithIgnoreCase(String text, String suffix) {
        return text.toLowerCase().endsWith(suffix.toLowerCase());
    }

    public static void main(String[] args) {
        String report = "Annual-Report.PDF";

        System.out.println(endsWithIgnoreCase(report, ".pdf"));
    }
}

true

public class SuffixVsPrefix {
    public static void main(String[] args) {
        String url = "https://codetofun.com/java";

        System.out.println("endsWith /java:    " + url.endsWith("/java"));
        System.out.println("startsWith https:  " + url.startsWith("https"));
        System.out.println("contains codetofun: " + url.contains("codetofun"));
    }
}

endsWith /java:    true
startsWith https:  true
contains codetofun: true

🚀 Common Use Cases

• File extension filters — accept only .java, .csv, or .json uploads.
• URL and path rules — verify routes end with / or a version segment.
• Input validation — ensure IDs or codes end with a required checksum digit.
• Log parsing — branch logic when a line ends with an error marker.
• Data cleanup — detect values that still end with unwanted whitespace characters before trimming.

📝 Notes

• endsWith() is case-sensitive unless you normalize case first.
• It checks only the suffix at the end—not the beginning or middle of the string.
• endsWith("") always returns true for any string.
• Include punctuation such as the dot in extensions: ".java" not "java" unless intended.
• For prefix checks, use startsWith(); for anywhere-in-text checks, use contains().

⚡ Optimization

endsWith() is optimized for suffix matching and is the right default for extension and trailing-pattern checks. If you call the same check repeatedly in a hot loop, store the boolean result in a local variable. For very large strings in performance-critical code, avoid redundant case conversions—normalize once and reuse the lowered copy.

💡 Best Practices