在 Java 中不使用多余变量交换两个字符串

public class Test {

	public static void main(String[] args) {

		String a = "Hello";

		String b = "World";

		System.out.println("Strings before swap: a = " + a + " and b = " + b);

		a = a + b;

		b = a.substring(0, a.length() - b.length());

		a = a.substring(b.length());

		System.out.println("Strings after swap: a = " + a + " and b = " + b);

	}

}

Strings before swap: a = Hello and b = World

Strings after swap: a = World and b = Hello