Delete JS object (row) from another object given the first

Question

In JavaScript, how can an object or row be deleted from another object that contains it given the first?

var apple = { 'color': 'red', 'price': 100, 'origin': 'Japan' };
var fruits = { Object, Object, Object }; // objects: apple, orange, mango
delete fruits[apple]; // this does not work

The 'delete fruits[apple]' or it's other forms as explained in this SO thread are not working.

Is removing an 'object1' from an 'object2' possible by just providing 'object1' as a parameter as indicated before?

The method indicated in Deleting a row from javascript object:

var newFruits = fruits.filter(function( apple ) {
  return fruits.color != apple.color &&
      fruits.price != apple.price && 
      fruits.origin != apple.origin;
});

Does not work either.

Edit

The fruits just contains rows of { 'color', 'price' , 'origin' } hence the last method. I actually need to compare these three components from a new array that might be inside the fruits array.

Is `fruits` an array? FYI, you implemented the method presented in the other question incorrectly. If `fruits` is your array then it won't have a property `color`. — Felix Kling, Dec 05 '13 at 03:04
is the variable fruits is array or Object? because if you want delete the variable you need some id or name to related. — Guilherme Soares, Dec 05 '13 at 03:05
Example if fruits is object but the key is fruits = {'apple':{values}}. Okay you only need put delete fruits['apple'] — Guilherme Soares, Dec 05 '13 at 03:06
Hello everyone. I updated the question. @GuilhermeSoares, unfortunately in my situation, I don't have a single key but unique combinations of keys. — , Dec 05 '13 at 03:09

score 1 · Accepted Answer · answered Dec 05 '13 at 03:09

The correct application of the method from the other question would be:

var apple = { 'color': 'red', 'price': 100, 'origin': 'Japan' };
var newFruits = fruits.filter(function( obj ) {
  return obj.color != apple.color &&
      obj.price != apple.price && 
      obj.origin != apple.origin;
});

You tried to access fruits.color, which always returns undefined since arrays don't have a color property. Instead, you have to compare the properties of each element of the array against your reference object. I suggest to have a look at the MDN documentation to learn how .filter works (which arguments it expects, which arguments get passed to the callback, etc).

Thank you. How will I make this dynamic? As in how do I pass a new variable that can replace `apple`? — , Dec 05 '13 at 03:11
Make a function that accepts an array and a reference object, and put the code inside that function. — Felix Kling, Dec 05 '13 at 03:12

score 0 · Answer 2 · answered Dec 05 '13 at 04:02

How resolve this bugs:

The frist you need some key to get values:

Model

Example if you working if fruits:

var fruits = 
{
    "apple": { 
        'color': 'red', 
        'price': 100, 
        'origin': 'Japan' 
    }

    //other fruits
}

How delete some fruit from variable fruits

it's easy only need this code below:

delete fruits['apple'];

Method filter

I didn't understand why did you use it to try delete.

var newFruits = fruits.filter(function( apple ) {
  return fruits.color != apple.color &&
      fruits.price != apple.price && 
      fruits.origin != apple.origin;
});

Refactory I create class to manipulate fruits

var Fruits = function(){
    this.values = {
        "apple": { 
            'color': 'red', 
            'price': 100, 
            'origin': 'Japan' 
        }
    }

    this.filter = function(obj){
        var f = {}; //list of fruits

        //Loop in all fruits
        for(var name in this.values){

            var fruit = this.values[name];
            var validFruit = true;

            //Check the obj values..
            for(prop_name in obj){

                var prop_value = obj[prop_name];

                if((typeof fruit[prop_name] === "undefined") || (fruit[prop_name] !== prop_value)){
                    validFruit = false; //Is not valid
                }
            }

            if(validFruit === true){
                f[name] = fruit;
            }
        }

        return f;
    };

    this.deleteIfHas = function(obj){
        var list = this.filter(obj);
        for(var key in list){
            delete this.values[key];
        }
    }

    this.setFruit = function(name, info){
        this.values[name] = info;
    }

    this.getFruit = function(name){
        return (typeof this.values[name] !== "undefined") ? this.values[name] : false;
    }
}

Testing..

var classFruit = new Fruits();
console.log(classFruit.filter({"origin":"Japan"})); // {"apple":{values of apple}}
classFruit.deleteIfHas({"origin":"Japan"}); //Delete apple
console.log(classFruit.values); //return {} because i delete apple