Learn to repeat a given string N times, to produce a new string which contains all the repetitions, though a simple Java program. We will use method Sting.repeat(N) (since Java 11) and using regular expression which can be used till Java 10.
1. String.repeat() API [Since Java 11]
This method returns a string whose value is the concatenation of given string repeated count
times. If the string is empty or count
is zero then the empty string is returned.
1.1. Syntax
/** * Parameters: * count - number of times to repeat * * Returns: * A string composed of this string repeated count times or the empty string if this string is empty or count is zero * * Throws: * IllegalArgumentException - if the count is negative. */ public String repeat(int count)
1.2. Example
Java program to repeat string ‘Abc’ to 3 times.
public class Main { public static void main(String[] args) { String str = "Abc"; System.out.println( str.repeat(3) ); } }
Program output.
AbcAbcAbc
2. Repeat string using regex [till Java 10]
If you are working on JDK <= 10, then you may consider using regex to repeat a string N times.
Java program to repeat string ‘Abc’ to 3 times.
public class Main { public static void main(String[] args) { String str = "Abc"; String repeated = new String(new char[3]).replace("\0", str); System.out.println(repeated); } }
Program output.
AbcAbcAbc
3. Apache Common’s StringUtils class
If regex is not what you are looking for – then you can use StringUtils class and it’s method repeat(times).
import org.apache.commons.lang3.StringUtils; public class Main { public static void main(String[] args) { String str = "Abc"; String repeated = StringUtils.repeat(str, 3); System.out.println(repeated); } }
Program output.
AbcAbcAbc
Drop me your questions related to how to repeat a string N times in Java.
Happy Learning !!
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