Java中將兩個字符串的值交換

用String中的substring函數

思路：

substring(int beginIndex)函數從beginIndex截取到末尾

substring(int beginIndex, int endIndex)函數從beginIndex截取到endIndex-1下標的字符串

String a = "abc";

String b = "ghijk";

String temp = a + b;

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

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