what is the best way to fetch property list from json array

Question

I want to fetch a property list from a json array. below is json array

[ { treeName: 'tree_A', prefix: 'prefix' }, { treeName: 'tree_b', prefix: 'prefix1/' } ]

After running code, my expectation result is ["tree_A","tree_B"];

Below is my implementation:

var treeNames = [];
        for (var index = 0; index < config.treeSources.length; index++) {
            treeNames.push(config.treeSources[index].treeName);
        }

I want to find a best implementation to make code beautiful..

any one want to play it?

lodash version:`_.forEach(config.treeSources, function (source) { treeNames1.push(source.treeName); });` — Linqtoxml, Apr 16 '15 at 03:05
is there any function in javascript like C# lambda `var result = list.select(x=>x.treeNmae).list();`? — Linqtoxml, Apr 16 '15 at 03:07
*"I want to find a best implementation to make code beautiful'* How do you define "best"? Is the "best" implementation the shortest? The one the uses the least memory? Least CPU? The one that is most compatible with existing runtimes? — Felix Kling, Apr 16 '15 at 03:11
Actually I want "to make code beautiful". it looks like short and have good a understanding, but your question is useful for me(new boy in javascript). It makes my eyes brightened. — Linqtoxml, Apr 16 '15 at 03:19

score 2 · Accepted Answer · answered Apr 16 '15 at 03:06

2

Check out Lodash/Underscore's _.pluck function. It does exactly what you want:

var treeNames = _.pluck(config.treeSources, 'treeName')

Using an entire utility library like Lodash or Underscore is probably overkill if your only going to use it for this one function, however, although they do provide a wide variety of very useful other functions.

answered Apr 16 '15 at 03:06

tomb

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Please, if this answer solves your question, set it as the accepted answer by clicking the green tick beside the question ;) – tomb Apr 16 '15 at 03:12
you can avoid lodash if all you need is pluck: `function pluck(x){ "use strict"; return x[this];}`, then use it anytime with [].map() (or filter): `config.treeSources.map(pluck, 'treeName');` – dandavis Apr 16 '15 at 03:50

score 0 · Answer 2 · answered Apr 16 '15 at 03:05

I'll do it something like bellow using native map

var data = [ { treeName: 'tree_A', prefix: 'prefix' }, { treeName: 'tree_b', prefix: 'prefix1/' } ];
var treeNames = data.map(function (tree) {
    return tree.treeName;
});

console.log(treeNames);

Note:- The IE8 doesn't support map function, so if want this on IE8 you have to use native for loop or some library like underscorejs.

what is the best way to fetch property list from json array

2 Answers2