m0_48987868的博客

public static void testSpeed() { final int N = 150000; String str1 = ""; long start = System.currentTimeMillis(); for(int i = 0;i < N;i++) { str1 +="*"; } System.out.println("耗时：" + (System.currentTimeMillis() - start)); StringBuffer str2 = n

package com.xiaoliu; import java.util.Scanner; import javax.swing.JOptionPane; public class GoodsDome { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); Goods[] goodsArray = new Goods[10]; int i = 0; while(tru

包装类 1.装箱 2.拆箱 pblic static void main(String[] args){ int num1 = 10; //打包基本类型（装箱） Integer iNum1 = new Integer(num1); Integer iNum2 = num1; //自动装箱 //自动装箱操作，相当于调用了Integer的静态方法valueOf iNum2 = Integer.valueOf(num1); int num2 = iNum2.intValue(); //拆箱 in