Java String repeat() Method

The String.repeat() method in Java is used to repeat a string a specified number of times. This guide will cover the method's usage, explain how it works, and provide examples to demonstrate its functionality.

Table of Contents

1. Introduction
2. repeat Method Syntax
3. Examples
   • Repeating a String
   • Handling Edge Cases
4. Conclusion

Introduction

The String.repeat() method is a member of the String class in Java, introduced in Java 11. It allows you to create a new string that consists of the original string repeated a specified number of times.

repeat Method Syntax

The syntax for the repeat method is as follows:

public String repeat(int count)

• count: The number of times the string should be repeated.

Examples

Repeating a String

The repeat method can be used to repeat a string a specified number of times.

Example

public class RepeatExample {
    public static void main(String[] args) {
        String str = "Hello";

        String repeatedStr = str.repeat(3);

        System.out.println("Original string: " + str);
        System.out.println("Repeated string: " + repeatedStr);
    }
}

Output:

Original string: Hello
Repeated string: HelloHelloHello

Handling Edge Cases

The repeat method handles edge cases such as repeating a string zero times or with a negative count.

Example

public class RepeatExample {
    public static void main(String[] args) {
        String str = "Hello";

        String repeatedZeroTimes = str.repeat(0);

        System.out.println("Repeated zero times: '" + repeatedZeroTimes + "'");

        try {
            String repeatedNegativeTimes = str.repeat(-1);
            System.out.println("Repeated negative times: '" + repeatedNegativeTimes + "'");
        } catch (IllegalArgumentException e) {
            System.out.println("Error: " + e.getMessage());
        }
    }
}

Output:

Repeated zero times: ''
Error: count is negative: -1

Repeating an Empty String

Repeating an empty string will always result in an empty string, regardless of the count.

Example

public class RepeatExample {
    public static void main(String[] args) {
        String str = "";

        String repeatedStr = str.repeat(5);

        System.out.println("Repeated empty string: '" + repeatedStr + "'");
    }
}

Output:

Repeated empty string: ''

Conclusion

The String.repeat() method in Java is used for repeating strings a specified number of times. By understanding how to use this method, you can efficiently create repeated strings in your Java applications. Whether you are repeating a string multiple times, handling edge cases, or dealing with empty strings, the repeat method provides a reliable solution for these tasks.