摘要： 闲话不多，先看一段代码public class test { public static void main(String[] args) { String str1 = "hello"; //方法1 String str2 = "hel"+"lo"; //方法2 String str3 = "hel"; str3 = str3 + "lo"; System.out.println("str1 == str2 :" + (str1 == str2)); System.out. 阅读全文