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What is StringUtils.repeat() in Java?

abhilash

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repeat() is a staticthe methods in Java that can be called without creating an object of the class. method of the StringUtils class that is used to repeat a given string/character a number of times to form a new string. The method also takes a string separator that is injected each time.

How to import StringUtils

The definition of StringUtils can be found in the Apache Commons Lang package, which we can add to the Maven project by adding the following dependency to the pom.xml file:


<dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.12.0</version>
</dependency>

For other versions of the commons-lang package, refer to the Maven Repository.

You can import the StringUtils class as follows.


import org.apache.commons.lang3.StringUtils;

Syntax


public static String repeat(final String str, final String separator, final int repeat)

Parameters

final String str: The string to repeat.

final String separator: The string separator to inject.

final int repeat: The number of times to repeat.

Return value

This method returns a new string with the given string repeated repeat number of times.

Overloaded methods

  • public static String repeat(final String str, final int repeat)
  • public static String repeat(final char ch, final int repeat)

Code

Example 1

  • string = "educative"
  • repeat = 3
  • separator = "-"

The method returns educative-educative-educative, where the string is repeated three times with the string separator injected after every repetition.

Example 2

  • string = "educative"
  • repeat = 2

The method returns educativeeducative, where the string is repeated two times.

Example 3

  • string = null
  • repeat = 3

The method returns null, as the input string is null.

Example 4

  • string = "educative"
  • repeat = -1

The method returns `` as the number of times to repeat is -1, therefore it will be treated as zero.

import org.apache.commons.lang3.StringUtils;
public class Main {
public static void main(String[] args) {
// Example 1
String s = "educative";
int repeat = 3;
String separator = "-";
System.out.printf("The output of StringUtils.repeat() for the string - '%s' is '%s'", s, StringUtils.repeat(s, separator, repeat));
System.out.println();
// Example 2
s = "educative";
repeat = 2;
System.out.printf("The output of StringUtils.repeat() for the string - '%s' is '%s'", s, StringUtils.repeat(s, repeat));
System.out.println();
// Example 3
s = null;
repeat = 2;
System.out.printf("The output of StringUtils.repeat() for the string - '%s' is '%s'", s, StringUtils.repeat(s, repeat));
System.out.println();
// Example 4
s = "educative";
repeat = -1;
System.out.printf("The output of StringUtils.repeat() for the string - '%s' is '%s'", s, StringUtils.repeat(s, repeat));
System.out.println();
}
}

Output

The output of the code will be as follows.


The output of StringUtils.repeat() for the string - 'educative' is 'educative-educative-educative'
The output of StringUtils.repeat() for the string - 'educative' is 'educativeeducative'
The output of StringUtils.repeat() for the string - 'null' is 'null'
The output of StringUtils.repeat() for the string - 'educative' is ''

RELATED TAGS

java
communitycreator
repeat
stringutils

Grokking Modern System Design Interview for Engineers & Managers

Ace your System Design Interview and take your career to the next level. Learn to handle the design of applications like Netflix, Quora, Facebook, Uber, and many more in a 45-min interview. Learn the RESHADED framework for architecting web-scale applications by determining requirements, constraints, and assumptions before diving into a step-by-step design process.

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