1.二分查找，java的输入与输出

1 package com; 2  3  4 public class Firstapp{ 5     public static void main(String args[]) 6     { 7         java.util.Scanner sc=new java.util.Scanner(System.in); 8         int n,start,end,middle; 9         System.out.println("请输入：");10         n=sc.nextInt();11         int a[]={-2,1,4,5,8,12,17,23,45,56,90,100};12         start=0;13         end=a.length-1;14         middle=(start+end)/2;15         int count=0;16         while(n!=a[middle]){17             if(n>a[middle]){18                 start=middle;19             }20             else if(n
      
       a.length/2)    26                     break;27             }28         if(count>a.length/2)29             System.out.println(":"+n+"不在数组内");30         else31             System.out.println(":"+n+"是数组中第"+middle+"个元素");32         33         }34     }
      

 2.java的类与对象，new对对象进行初始化

1 package com; 2 class XiyouRenwu { float height,weight; 3 String head, ear,hand,foot,mouth; 4 void speak(String s) 5 {  6    head="歪着头"; 7    System.out.println(s); 8 } 9 }10 11 public class Exmple {    12     public static void main(String args[])13     {XiyouRenwu zhubajie,sunwukong;14     zhubajie=new XiyouRenwu();15     sunwukong=new XiyouRenwu();16     zhubajie.height=1.80f;                                //对象给自己的变量赋值。17     zhubajie.weight=160f;      18     zhubajie.hand="两只黑手";19     zhubajie.foot="两只大脚"; 20     zhubajie.head="大头"; 21     zhubajie.ear="一双大耳朵"; 22     zhubajie.mouth="一只大嘴"; 23     sunwukong.height=1.62f;                                //对象给自己的变量赋值。24     sunwukong.weight=1000f;    25     sunwukong.hand="白嫩小手";26     sunwukong.foot="两只绣脚"; 27     sunwukong.head="绣发飘飘"; 28     sunwukong.ear="一对小耳";  29     sunwukong.mouth="樱桃小嘴";30     System.out.println("zhubajie的身高："+zhubajie.height);31     System.out.println("zhubajie的头："+zhubajie.head);32     System.out.println("sunwukong的重量："+sunwukong.weight);33     System.out.println("sunwukong的头："+sunwukong.head);34     zhubajie.speak("俺老猪我想娶媳妇");                       //对象调用方法。35     System.out.println("zhubajie现在的头："+zhubajie.head);36     sunwukong.speak("老孙我重1000斤，我想骗八戒背我");         //对象调用方法。37     System.out.println("sunwukong现在的头："+sunwukong.head);38 39     }40 41 }