Access all properties inside an array of objects in Javascript

Question

If i have an array of objects, how can i iterate through it?

For example this array

[{ name: "objc1", size: "small" }, { first: "objc2", size: "medium" }, { first: "objc3", size: "Big" }]

I can access each object with this:

for (var key in collection){

  alert(collection[key])  

}

But how can i go inside the object, to each property?

score 1 · Accepted Answer · edited May 23 '17 at 10:30

1

Don' t use for ... in over arrays, this approach has several issues. The for ... in is actually made for iterating over properties. Therefore, use the following (ES6):

for (const item of collection) {
  for (const key in item) {
    alert(key+': '+item[key]);
  }
}

On ES5, you need a loop like this:

var item;
for (var i=0; i < collection.length; i++) {
  item = collection[i];
  for (var key in item) {
    alert(key+': '+item[key]);
  }
}

edited May 23 '17 at 10:30

Community

1
1

answered Nov 12 '16 at 15:05

Lucero

59,176
9
122
152

Im using chrome. :( – Nov 12 '16 at 15:09
Chrome is fine... supports many ES6 features already. – Lucero Nov 12 '16 at 15:10
It says : var for is available only in ES6. :(. Im using freecodecamp. – Nov 12 '16 at 15:12
I posted both ES6 and ES5 variants, the ES5 one should work (I just fixed a type though). – Lucero Nov 12 '16 at 15:13
It says item is not defined...:( – Nov 12 '16 at 15:14

score 0 · Answer 2 · answered Nov 12 '16 at 15:06

0

var collection = [{ name: "objc1", size: "small" }, { first: "objc2", size: "medium" }, { first: "objc3", size: "Big" }];
collection.forEach(item =>{
  for (property in item){
    console.log(item[property]);
  };
});

answered Nov 12 '16 at 15:06

BrTkCa

4,703
3
24
45

Access all properties inside an array of objects in Javascript

2 Answers2