Add key value pair to all objects in array

Question

I wanted to add a key:value parameter to all the objects in an array.

eg:

var arrOfObj = [{name: \'eve\'},{name:\'john\'},{name:\'jane\'}];
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Answer 1

Looping through the array and inserting a key, value pair is about your best solution. You could use the 'map' function but it is just a matter of preference.

var arrOfObj = [{name: 'eve'},{name:'john'},{name:'jane'}];
arrOfObj.map(function (obj) { 
   obj.isActive = true;
});

Answer 2

Simply use map function:

var arrOfObj = arrOfObj.map(function(element){
   element.active = true;
   return element;
}

Map is pretty decent on compatibility: you can be reasonably safe from IE <= 9.

However, if you are 100% sure your users will use ES6 Compatible browser, you can shorten that function with arrow functions, as @Sergey Panfilov has suggested.

Answer 3

Simply you can add that way. see below the console image

Answer 4

You may also try this:

arrOfObj.forEach(function(item){item.isActive = true;});

console.log(arrOfObj);

Answer 5

@Redu's solution is a good solution

arrOfObj.map(o => o.isActive = true;) but Array.map still counts as looping through all items.

if you absolutely don't want to have any looping here's a dirty hack :

Object.defineProperty(Object.prototype, "isActive",{
  value: true,
  writable: true,
  configurable: true,
  enumerable: true
});

my advice is not to use it carefully though, it will patch absolutely all javascript Objects (Date, Array, Number, String or any other that inherit Object ) which is really bad practice...

Answer 6

You can do this with map()

var arrOfObj = [{
  name: 'eve'
}, {
  name: 'john'
}, {
  name: 'jane'
}];

var result = arrOfObj.map(function(o) {
  o.isActive = true;
  return o;
})

console.log(result)

If you want to keep original array you can clone objects with Object.assign()

var arrOfObj = [{
  name: 'eve'
}, {
  name: 'john'
}, {
  name: 'jane'
}];

var result = arrOfObj.map(function(el) {
  var o = Object.assign({}, el);
  o.isActive = true;
  return o;
})

console.log(arrOfObj);
console.log(result);