Question

例如数组：

var arr = [
 {
  Test 0: 142.0465973851827,
  Test 1: 199,
  timestamp: "2017-01-16T00:00:00.000Z"
 },
 {
  Test 0: 142.0465973851827,
  Test 1: 199,
  timestamp: "2017-01-17T00:00:00.000Z"
 }
]

Test 0和Test 1可以是任何内容。我试着回复这样的结果：

var arr = [
 {
  total: 341,
  timestamp: '2017-01-16T00:00:00.000Z'
 },
 {
  total: 341,
  timestamp: '2017-01-17T00:00:00.000'
 }
]

这样做的正确循环类型是什么？

Answer 1

array.map，Object.keys，array.filter和array.reduce的组合可以做到这一点。使用array.map运行数组Object.keys以获取每个对象的键，array.filter仅获取以＆＃34; Test＆＃34;开头的键，然后使用累积结果array.reduce。

上述所有内容也可以使用简单的循环轻松完成。数组方法可以使用常规for循环完成，而Object.keys则需要for-in守护object.hasOwnProperty。

Answer 2

arr=arr.map(el=>{return el.total=Object.keys(el).filter(key=>key.split("Test")[1]).reduce((total,key)=>total+el[key],0),el;});

它完全与他的回答的第一部分中描述的梦想家约瑟夫完全相同。

Answer 3

您可以映射数组，然后在每个对象的Object.keys上运行reduce，不包括timestamp属性

var arr = [{
  Test0: 142.0465973851827,
  Test1: 199,
  timestamp: "2017-01-16T00:00:00.000Z"
}, {
  Test0: 142.0465973851827,
  Test1: 199,
  timestamp: "2017-01-17T00:00:00.000Z"
}]

var res = arr.map(v => ({
    total: Object.keys(v).reduce((a, b) => b !== 'timestamp' ? a + v[b] : a, 0),
    timestamp: v.timestamp    
}));

console.log(res);

Answer 4

像这样？

function number(v){ return +v || 0; }

arr.map(function(obj){
    var timestamp = obj.timestamp;
    var total = Object.keys(obj)
        .reduce(function(sum, key){
            return sum + number( obj[key] );
        }, 0);

    return { total, timestamp }

})

Answer 5

这个怎么样？

＆＃13;

var arr = [
 {
  Test0: 142.0465973851827,
  Test1: 199,
  timestamp: "2017-01-16T00:00:00.000Z"
 },
 {
  Test0: 142.0465973851827,
  Test1: 199,
  timestamp: "2017-01-17T00:00:00.000Z"
 }
];

var result = [];
var exclude = "timestamp";
arr.forEach(function(elements){
	var sum = 0;
	for(key in elements){
		if(key !== exclude){
			sum += elements[key];
		}
	}
	var newElement = {total: sum.toFixed(2), timestamp: elements.timestamp}
	result.push(newElement);
});

console.info(result);

＆＃13;

对象数组，按键求和，但密钥未知

5 个答案: