通过简单的Java程序，学习重复给定字符串N次，以产生包含所有重复的新字符串。无涯教程将使用方法 Sting.repeat(N)(因为Java 11)并使用常规方法该表达式可用于Java 10。
String.repeat()
此方法返回一个字符串，该字符串的值是给定字符串的重复 count 次的串联。如果字符串为空或 count 为零，则返回空字符串。
/** * 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)
Java程序将字符串" Abc"重复3次。
public class Main
{
public static void main(String[] args)
{
String str = "Abc";
</span><span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="pln">println</span><span class="pun">(</span><span class="pln"> str</span><span class="pun">.</span><span class="pln">repeat</span><span class="pun">(</span><span class="lit">3</span><span class="pun">)</span><span class="pln"> </span><span class="pun">);</span><span class="pln">
</span><span class="pun">}</span><span class="pln">
}
程序输出。
AbcAbcAbc
匹配重复字符串
如果您正在使用JDK <= 10，则可以考虑使用regex将字符串重复N次。
Java程序将字符串" Abc"重复3次。
public class Main
{
public static void main(String[] args)
{
String str = "Abc";
</span><span class="typ">String</span><span class="pln"> repeated </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">String</span><span class="pun">(</span><span class="kwd">new</span><span class="pln"> </span><span class="kwd">char</span><span class="pun">[</span><span class="lit">3</span><span class="pun">]).</span><span class="pln">replace</span><span class="pun">(</span><span class="str">"\0"</span><span class="pun">,</span><span class="pln"> str</span><span class="pun">);</span><span class="pln">
</span><span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="pln">println</span><span class="pun">(</span><span class="pln">repeated</span><span class="pun">);</span><span class="pln">
</span><span class="pun">}</span><span class="pln">
}
程序输出。
AbcAbcAbc
StringUtils类
如果不是正则表达式，则可以使用 StringUtils 类及其方法repeat(times)。
import org.apache.commons.lang3.StringUtils;
public class Main
{
public static void main(String[] args)
{
String str = "Abc";
</span><span class="typ">String</span><span class="pln"> repeated </span><span class="pun">=</span><span class="pln"> </span><span class="typ">StringUtils</span><span class="pun">.</span><span class="pln">repeat</span><span class="pun">(</span><span class="pln">str</span><span class="pun">,</span><span class="pln"> </span><span class="lit">3</span><span class="pun">);</span><span class="pln">
</span><span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="pln">println</span><span class="pun">(</span><span class="pln">repeated</span><span class="pun">);</span><span class="pln">
</span><span class="pun">}</span><span class="pln">
}
程序输出。
AbcAbcAbc
