Simple way to repeat a string
String::repeat
". ".repeat(7) // Seven period-with-space pairs: . . . . . . .
New in Java 11 is the method String::repeat
that does exactly what you asked for:
String str = "abc";
String repeated = str.repeat(3);
repeated.equals("abcabcabc");
Its Javadoc says:
/**
* Returns a string whose value is the concatenation of this
* string repeated {@code count} times.
* <p>
* If this string is empty or count is zero then the empty
* string is returned.
*
* @param count number of times to repeat
*
* @return A string composed of this string repeated
* {@code count} times or the empty string if this
* string is empty or count is zero
*
* @throws IllegalArgumentException if the {@code count} is
* negative.
*
* @since 11
*/
If you are using Java <= 7, this is as "concise" as it gets:
// create a string made up of n copies of string s
String.format("%0" + n + "d", 0).replace("0", s);
In Java 8 and above there is a more readable way:
// create a string made up of n copies of string s
String.join("", Collections.nCopies(n, s));
Finally, for Java 11 and above, there is a new repeat(int count)
method specifically for this purpose(link)
"abc".repeat(12);
Alternatively, if your project uses java libraries there are more options.
For Apache Commons:
StringUtils.repeat("abc", 12);
For Google Guava:
Strings.repeat("abc", 12);
Commons Lang StringUtils.repeat()
Usage:
String str = "abc";
String repeated = StringUtils.repeat(str, 3);
repeated.equals("abcabcabc");
Here is the shortest version (Java 1.5+ required):
repeated = new String(new char[n]).replace("\0", s);
Where n
is the number of times you want to repeat the string and s
is the string to repeat.
No imports or libraries needed.