issue in looping object in javascript

Question

I have some problem with my JavaScript

<html>
<body>
<p id="demo2"></p>
<script>
     var text = '{"h":["username","hair_color","height"],"d":[["ali","brown",1.2],["ma0072c","blue",1.4],["joe","brown",1.7],["zehua","black",1.8]]}';

     var obj = JSON.parse(text);
     var x= Object.keys(obj.h).length;
     var y= Object.keys(obj.d).length;

     var json_datas = JSON.stringify(obj.h);
     var json_data = JSON.stringify(obj.d);
     var obj2 = JSON.parse(json_data);
     var json_data2 = JSON.stringify(obj2[1]);
     var obj3 = JSON.parse(json_data2);
     var newjson = [];
     var newjson2 = [];
     i=0;
     l=0;
     z=0;
     m=0;
     var boys= {};
     for (i in obj.h){      
         boys[obj.h[i]] = obj.d[m][l];
         l++;
         z++;
         m++;
         newjson.push(boys);
     }
     newjson2 = newjson2.concat(newjson);
     var newjson2 = JSON.stringify(newjson);
     document.getElementById("demo2").innerHTML = newjson2; 
</script>
</body>
</html>

this script boys[obj.h[i]] = obj.d[m][l];

why the code doesn't want to loop? Can someone tell me the correct loop? I want the output like this

[{"username":"ali","hair_color":"brown","height":1.2},
 {"username":"marc","hair_color":"blue","height":1.4},
 {"username":"joe","hair_color":"brown","height":1.7},
 {"username":"zehua","hair_color":"black","height":1.8}]

but my output right now is like this

[{"username":"ali","hair_color":"brown","height":1.2},
 {"username":"ali","hair_color":"brown","height":1.2},
 {"username":"ali","hair_color":"brown","height":1.2},
 {"username":"ali","hair_color":"brown","height":1.2}]

@nishant ,well spotted

Billy
– Billy

2015-12-24 12:07:58 +00:00
Commented Dec 24, 2015 at 12:07 — Billy
– Billy, Commented Dec 24, 2015 at 12:07
And don't use for ..in loops on arrays

adeneo
– adeneo

2015-12-24 12:08:13 +00:00
Commented Dec 24, 2015 at 12:08 — adeneo
– adeneo, Commented Dec 24, 2015 at 12:08
@Nishant you don't need i++ in a for-in loop

mjlowky
– mjlowky

2015-12-24 12:27:05 +00:00
Commented Dec 24, 2015 at 12:27 — mjlowky
– mjlowky, Commented Dec 24, 2015 at 12:27

Stepashka · Accepted Answer · 2015-12-24 12:16:47Z

3

I'd suggest to improve the loop code to something like this:

var newjson2 = [];
obj.d.forEach(function(element) {
  var k = {};
  element.forEach(function(element, i){
    k[obj.h[i]] = element;
  })
  newjson2.push(k);
})

Looks clearer and more robust for me...

answered Dec 24, 2015 at 12:16

Stepashka

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Comments

Astaroth · Accepted Answer · 2015-12-24 13:26:00Z

0

for (a in b) loops just iterates over object properties. To iterate over array elements use the forEach loop.

obj.h.forEach(function(element, idx, arr){
   boys[arr[element]] = obj.d[m][l];
   l++;
   z++;
   m++;
   newjson.push(boys);
});

Being the variable arr a reference to obj.h.

answered Dec 24, 2015 at 13:26

Astaroth

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Comments

Oriol · Accepted Answer · 2015-12-25 00:07:54Z

0

I don't know why you used a lot of code for getting this result. You can use this code:

<html>
<body>
 <p id="demo2"></p>
 <script>
   var text = '{"h":["username","hair_color","height"],"d":[["ali","brown",1.2],["ma0072c","blue",1.4],["joe","brown",1.7],["zehua","black",1.8]]}';

   var obj = JSON.parse(text);
   var newjson = [];
   for (var i = 0 ; i < obj.d.length; i++){ 
    var boys= {};
    for(var j= 0; j < obj.h.length; j++) {
      boys[obj.h[j]] = obj.d[i][j];    
    }
    newjson.push(boys);
   }
  document.getElementById("demo2").innerHTML = JSON.stringify(newjson);
</script>

edited Dec 25, 2015 at 0:07

Oriol

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answered Dec 24, 2015 at 12:33

Feroj Bepari

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