《Java实战开发经典》第四章4.8

> package four; //4.8统计0~9这几个数字分别出现了多少次 public class Eight {   public
> static void main(String[] args) {     int arr[]=
> {0,4,5,7,3,9,8,4,1,6,3,5,7,8,9,3,2,5,7
>                       ,3,6,2,1,4,6,7,7,8,4,9};    int i=0;    int n0=0, n1=0,n2=0,n3=0,n4=0,n5=0,n6=0,n7=0,n8=0,n9=0;
>   for(i=0;i<arr.length;i++){      switch(arr[i]){             case 0:{
>               n0++;
>               continue;           }           case 1:{
>               n1++;
>               continue;           }           case 2:{
>               n2++;
>               continue;           }           case 3:{
>               n3++;
>               continue;           }           case 4:{
>               n4++;
>               continue;           }           case 5:{
>               n5++;
>               continue;           }           case 6:{
>               n6++;
>               continue;           }           case 7:{
>               n7++;
>               continue;           }           case 8:{
>               n8++;
>               continue;           }           case 9:{
>               n9++;
>               continue;           }       }     }     System.out.println("0出现的次数为:"+n0);  System.out.println("1出现的次数为:"+n1);
>   System.out.println("2出现的次数为:"+n2);
>   System.out.println("3出现的次数为:"+n3);
>   System.out.println("4出现的次数为:"+n4);
>   System.out.println("5出现的次数为:"+n5);
>   System.out.println("6出现的次数为:"+n6);
>   System.out.println("7出现的次数为:"+n7);
>   System.out.println("8出现的次数为:"+n8);
>   System.out.println("9出现的次数为:"+n9);  } }


=====分割线，方法二============
package xiti4;
//30个0~9间的数字，分别统计0~9共出现多少次
public class Eighth {
public static void main(String[] args) {
    for(int i=0;i<10;i++){
        fun(i);
    }
  }
public static void fun(int x){
    int arr[]={4,1,0,4,6,7,8,9,2,3,5,1,3,4,2,5
            ,6,7,8,0,1,2,4,6,7,4,3,4,5,2};
        int num=0;
            for(int a=0;a<30;a++){
                if(x==arr[a]){
                    num++;
                }
    }
            System.out.println(x+"出现了"+num+"次");
}
}