Question

这是我的数组

Array1 = [{year: "2013", fruit: "banana", quantity: 1},{year: "2014", fruit: "orange", quantity: 1},{year: "2014", fruit: "banana", quantity: 2}]

我的功能是复制Array1：

var Array2 = Array1; 
for (var i = 0, len = Array1.length; i < len; i++) {
    Array2[i] = Array1[i];
}

但我想在Array2中将所有值更改为我的键“year”并将值设为“AllYear”：

Array2 = [{year: "AllYear", fruit: "banana", quantity: 1},{year: "AllYear", fruit: "orange", quantity: 1},{year: "2014", fruit: "banana", quantity: 2}]

Answer 1

使用map，但请确保返回新对象：

var Array2 = Array1.map(function (el) {
  return { fruit: el.fruit, year: 'AllYear', quantity: el.quantity }
});

DEMO

Answer 2

// js

 var Array2 = Array1 
  for (var i = 0, len = Array1.length; i < len; i++) {
    Array2[i].year = "AllYear";
}

参考此解决方案：Jsfiddle

我希望这会有所帮助！

Answer 3

你可以这样做

Array2 = Array1.slice(0); //copy array1 elements to array2
Array2 = Array2.map(function (el) {
var copy = {};
 for (var attr in el) {
        if (el.hasOwnProperty(attr)) copy[attr] = el[attr];
    }
  copy.year = 'AllYear';
  return copy ;
});

Answer 4

init_printing

更改数组对象的值

4 个答案: