Question

JS计算数组个数？

var t = [{value:'待料停'},{value:'运行'},{value:'其他停'},{value:'离线'},{value:'断纱停'},{value:'关机'},{value:'关机'},]
var res = [{value:'待料停',conut:0},{value:'运行',conut:0},{value:'其他停',conut:0},{ value:'离线',conut:0},{ value:'断纱停',conut:0},{value:'关机',onut:0},{value:'7',conut:0}]

我想要计算t.value的个数，然后放到res对应的count中去，这个应该怎么实现？

Answer 1

var t = [{value:'待料停'},{value:'运行'},{value:'其他停'},{value:'离线'},{value:'断纱停'},{value:'关机'},{value:'关机'}]

for(var i of t){

var count = 0

for(var j of t){

if(j.value === i.value){

count++

}

}

i.count = count

}

console.log(t)

嫌循环太麻烦,也可以这样简化:

var t = [{value:'待料停'},{value:'运行'},{value:'其他停'},{value:'离线'},{value:'断纱停'},{value:'关机'},{value:'关机'}]

var res = Array.from(t,item => {

item.count = t.filter(j => j.value === item.value).length

return item

})

console.log(res)

Answer 2

var t=[{value:'待料停'},{value:'运行'},{value:'其他停'},{value:'离线'},{value:'断纱停'},{value:'关机'},{value:'关机'},];
var res=[{value:'待料停',count:0},{value:'运行',count:0},{value:'其他停',count:0},{ value:'离线',count:0},{ value:'断纱停',count:0},{value:'关机',count:0},{value:'7',count:0}];
t.forEach(e=>{
let r=res.find(e1=>e1.value==e.value);
if(r)r.count++
});
console.log(res);

Answer 3

设置一个全局变量对数据进行循环 判断数据类型为数组 全局变量+1
或者去检索“[”并且计算出数量