Question

我有不同对象的数组，如下所示：

[{
   color:'red',
   'type':'2',
   'status':'true'
 }
 {
   color:'red',
   'type':'2',
   'status':'false'
 }]

我想过滤像status这样的元素，然后计算过滤后的内容，例如，如果status为false，则返回1.

我尝试过以下代码，但我不确定我在这做什么：

for (i = 0; i < check.length; i++) {
  var check2;

  console.log(check[i].isApproved);
  (function(check2) {
    return check2 = check.filter(function(val) { 
        return val == false 
    }).length;
  })(check2)

  console.log('again Rides',check2);
}

Answer 1

如果我理解正确，您想要计算status等于'false' 注意的元素数量：status中的值是字符串

var check = [
  { color:'red', 'type':'2', 'status':'true' }, 
  { color:'red', 'type':'2', 'status':'false' } 
];

var countfiltered = check.filter(function(element){
    return element.status == 'false';
}).length

console.log(countfiltered);

Answer 2

好吧，你可以做一个计数，或者你可以运行一个过滤器并获得最终数组的长度。

var count = 0;
var arr = [{color:'red', type:'2', status:'true'},
           {color:'red', type:'2', status:'false'} ];
// Showing filterin to be robust. You could just do this in 
// a loop, which would be sensible if you didn't need the subarray. 
var filtered = arr.filter ( function ( d ) {
    // Note that I'm testing for a string, not a boolean, because
    // you are using strings as values in your objects. 
    // If it was a boolean, you'd use if ( d.status ) { ... }
    count++;
    return d.status === 'false';
});

// These should be the same, reflecting number of objs with 'false'
console.log ( count );
console.log ( filtered.length );
// This should trace out a sub array of objs with status === 'false'
console.log ( filtered );

Answer 3

仅添加最新语法和更具可读性的IMO：

const items = [
  { color:'red', type:'2', status:'true' }, 
  { color:'red', type:'2', status:'false' } 
];

const statusFalseCount = items.filter(e => e.status === 'false').length;

console.log(statusFalseCount); // => 1

过滤对象数组并在Javascript

3 个答案: