Check if array contains object without reference

Question

I have the following function:

function containsObject(object, array) {
    for (var i = 0; i < array.length; i++) {
        if (array[i] === object) {
            return i;
        }
    }

    return false;
}

The following array:

var array = [
    {
        name: 'test1',
        age: 12
    },
    {
        name: 'test2',
        age: 14
    }
];

And I need to check if the following object is in the array:

var object = {
    name: 'test1',
    age: 12
};

But when I use the function to check if the array contains the object:

console.log(containsObject(object, array));

It will return false, since the references of the objects aren't the same. So technically speaking, the objects aren't the same.

How do I go on about this without sharing references?

Answer 1

Fiddle : https://jsfiddle.net/thatOneGuy/3ys6s7sy/2/

Youll have to check each element of the object with each element of the other object.

function containsObject(object, array) {
  for (var i = 0; i < array.length; i++) {
    var count = 0;
    var matching = true;
    for (var key in object) {
      if (array[i][key] === object[key]) {
        matching = true;
        if (count == Object.keys(array[i]).length - 1 && matching) {
          return i;
        } else {
          count++;
        }
      } else {
        matching = false;

      }
    }
  }
  return false;
}

var array = [{
  name: 'test2',
  age: 14
}, {
  name: 'test1',
  age: 12
}];

var thisObject = {
  name: 'test1',
  age: 12
};

console.log(containsObject(thisObject, array));

I changed the data around to see if it works. It now logs 'i' correctly. This would be quite slow if you have a lot of data to compare. You can always stringify the two objects and compare the two strings ?

Here is that function :

function containsObject(object, array) {
  for (var i = 0; i < array.length; i++) {
    for (var key in object) {
      //if (array[i][key] === object[key]) {
      //  return i;
      //}
      if (JSON.stringify(array[i]) === JSON.stringify(object)) {
            return i;
        }
    }
  }
  return false;
}

As mentioned in the comments the first one wouldn't cater for deep comparison. Whereas the stringify would. I would be careful about the objects being in different order though. For example if you use this object :

var thisObject = {
  age: 12,
  name: 'test1'
};

To compare, it wouldn't work as its just a straight string comparison.

Fiddle with stringify : https://jsfiddle.net/thatOneGuy/3ys6s7sy/1/