如何从对象的多元素数组中获取单个元素数组？

This is my array :

这是我的阵列:

mapping = [{sl_no : 1, type : "A", parent : ""},{sl_no : 2, type : "B", parent : "A"},{sl_no : 3, type : "D", parent : "B"}]

I want the array in the bellow format :

我希望数组采用以下格式:

mapped_sl_no = [{sl_no : 1},{sl_no : 2},{sl_no : 3}]

4 个解决方案

#1

Map is your friend...

地图是你的朋友......

   var mapped = mapping.map(function(item) { return item.sl_no; });

#2

I suggest to use Array#map() with a temporary object inside.

我建议使用带有临时对象的Array#map()。

var mapping = [{ sl_no: 1, type: "A", parent: "" }, { sl_no: 2, type: "B", parent: "A" }, { sl_no: 3, type: "D", parent: "B" }],
    mapped_sl_no = getMapped(mapping, 'sl_no');

function getMapped(array, k) {
    return array.map(function (a) {
        var o = {};
        o[k] = a[k];
        return o;
    });
}

document.write('<pre>' + JSON.stringify(mapped_sl_no, 0, 4) + '</pre>');

#3

Solution with map function:

地图功能解决方案:

var mapping = [{sl_no : 1, type : "A", parent : ""},{sl_no : 2, type : "B", parent : "A"},{sl_no : 3, type : "D", parent : "B"}];

var arr = mapping.map(function(obj){
  return {'sl_no': obj.sl_no};

})

console.log(arr); // the output is: [{sl_no : 1},{sl_no : 2},{sl_no : 3}]

#4

var mapped_sl_no = [];

mapping.forEach(function(mapVal){
    mapped_sl_no.push({sl_no:mapVal.sl_no});
});

This should do it for you.

这应该为你做。

Else you can use libraries like underscore(http://underscorejs.org/) or lowdash(https://lodash.com/)

否则你可以使用像下划线(http://underscorejs.org/)或lowdash(https://lodash.com/)这样的库

#1