How to convert a object array into string in JavaScript?

Question

The array is this:

[{name:'name1',id:'id1',val:'001},
 ...
 {name:'name10',id:'id10',val:'010}]

We want to store in the database as a long text string:

name1,id1,001;...;name10,id10,010

values separated by semicolon and comma.

Is there any convenient join or something else to achieve it? (I guess there must be something better than for loop.)

If you are happy with Jquery then this one is easy: http://jsfiddle.net/XWCv8/413/ And since the question is not tagged with Jquery I cant add it as answer :( — Rahul Tripathi, Apr 23 '15 at 18:54
Since that's not an array, but an object, you cannot use `join`, and won't get deterministic order unless you are explicit. — Bergi, Apr 23 '15 at 18:58

maerics · Accepted Answer · 2015-04-23T19:12:04.407

3

function joinValues(arr, j1, j2) {
  return arr.map(function(o) {
    return Object.keys(o).map(function(k) {
      return o[k];
    }).join(j1)
  }).join(j2);
}

var obj = [{a:1,b:2},{a:'x',b:'y'}];
joinValues(obj, ',', ';'); // => "1,2;x,y"

edited Apr 23 '15 at 19:12

answered Apr 23 '15 at 18:56

maerics

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Awesome! That is certainly beautiful JavaScript. Thanks a lot. – Blaise Apr 24 '15 at 01:06

score 2 · Answer 2 · edited May 23 '17 at 10:24

array.map(function(o){
  var values = Object.keys(o).map(function(key){
    return o[key];
  });
  return values.join(',');
}).reduce(function(a,b){
  return a + ';' + b;
});

Beware there might be compat issues depending on your platform (map, reduce, Object.keys not available everywhere yet!)

Also, take into account that properties order in regular objects is not guaranteed. With this approach, theoretically you could end up having name1,id1,001;...;id10,name10,010. That might be an issue when mapping the string back to objects.

score 1 · Answer 3 · answered Apr 23 '15 at 18:59

I'm afraid there isn't a built-in language feature for that, but if you can use ES6, it can look quite elegant

Object.values = obj => Object.keys(obj).map(key => obj[key]);

// so to convert your data
data.map(o => Object.values(o).join(',')).join(';');

How to convert a object array into string in JavaScript?

3 Answers3