★C语言 for语句的一个小程序求解

#include
main()
{ char s[]="012xy\08s34f4w2"; //这里是字符数组，里面存放的是字符
int i,n=0;
for(i=0;s[i]!=0;i++) //这里的 s[i] 是一个字符；将其ASCII码值 与0比较
if(s[i]>='0'&&s[i]<='9') n++;
printf("%d\n",n);
}

char s[]="012xy\08s34f4w2"; //存放到数组里的内容为
s[0] = '0' ,其ASICC码值为48 不等于0
s[1] = '1' ,其ASICC码值为49 不等于0
s[2] = '2' ,其ASICC码值为50 不等于0
s[3] = 'x' ,其ASICC码值为120 不等于0
s[4] = 'y' ,其ASICC码值为121 不等于0
s[5] = '\0' ,该字符为字符串结束符，其ASCII码值为0 因此循环一直要进行到这里才会退出for循环
程序功能是计算字符数组中 在出现结束符之前的字符中有多少个数字字符
因此答案为三个 （0、1、2）， 输出的n的值为3
请注意 数字字符 与数字的差别即：
'0' - 0 = 48 // 数字字符与对应数字的 差值为整数十进制48 可参考ASCII码值表
'9' - 9 = 48

function getData()
{
return new Promise((resolve, reject)=>{
var arr = [];
var i=0,len = 3;
for(;i<len;i++)
{
//通过 request 向后台发送请求,把数据添加到 arr 数组里面，当长度相同时执行回调函数
request()then(res=>{
arrpush(res);
if(arrlength === len)resolve(arr);
})
}
});
}
getData()then(res=>{
consolelog(res);
})catch(res=>{
consolelog(res);
})

讲解下循环输出元素
这里写描述
这里写描述
后台存储的数据给事
{
var local_database = [
{
date: "Sep 18 2016",
post_title:"冬日校花",
post_image: "/images/1jpg",
text: "美呀，美呀",
view_num: 112,
collect_num: 96,
turn_num: 515,
author_img: "/images/6jpg",
author:"高晴",
dateTime:"24小时",
detail:"我爱你，爱的如此深沉",
postId:0,
music:{
url: 'down/46993mp3',
title: "雪の华-南条爱乃",
coverImg: "/music/photo_new/T002R150x150M000001TEc6V0kjpVCjpgmax_age=2592000"
},
},
{
date: "Sep 18 2016",
post_title: "冬日校花",
post_image: "/images/2jpg",
text: "美呀，美呀",
view_num: 112,
collect_num: 96,
turn_num: 515,
author_img: "/images/6jpg",
author: "高晴",
dateTime: "24小时",
detail: "我爱你，爱的如此深沉",
postId: 1,
music: {
url: '/yq/5092537mp3',
title: "爱你-陈芳语",
coverImg: "/music/photo_new/T002R150x150M000001TEc6V0kjpVCjpgmax_age=2592000"
},
},
{
date: "Sep 18 2016",
post_title: "冬日校花",
post_image: "/images/3jpg",
text: "美呀，美呀",
view_num: 112,
collect_num: 96,
turn_num: 515,
author_img: "/images/6jpg",
author: "高晴",
dateTime: "24小时",
detail: "我爱你，爱的如此深沉",
postId: 2,
music: {
url: '/yq/204586755mp3',
title: "云烟成雨-房东的猫",
coverImg: "music/photo_new/T002R150x150M000001TEc6V0kjpVCjpgmax_age=2592000"
},
},
{
date: "Sep 18 2016",
post_title: "冬日校花",
post_image: "/images/4jpg",
text: "美呀，美呀",
view_num: 112,
collect_num: 96,
turn_num: 515,
author_img: "/images/6jpg",
author: "高晴",
dateTime: "24小时",
detail: "我爱你，爱的如此深沉",
postId: 3,
music: {
url: '/yq/213919334mp3',
title: "Your Song-Lady Gaga",
coverImg: ">