package Stringbuild_in_loop; public class Stringbuild_in_loop { public void Stringbuild_in_loop_bad() { String a = "test"; for (int i = 0; i < 5; i++) { a = a + "
"; // bad 循环中拼接字符串 } } public void Stringbuild_in_loop_good() { StringBuilder a = new StringBuilder("test"); for (int i = 0; i < 5; i++) { a.append("
"); // good 循环中拼接字符串 } } }