How To Delete A Javascript Object Item By Value?

Take, for instance, the following object: var fruits = { 'red' : 'apple', 'blue' : 'blueberry', 'yellow' : 'banana' } I know I can use delete fruits['red'] to remove i

Solution 1:

Have you tried something like this?

function deleteByValue(val) {
    for(var f in fruits) {
        if(fruits[f] == val) {
            delete fruits[f];
        }
    }
}

And as per Rocket's comment, you might want to check hasOwnProperty to make sure you aren't deleting members of the object's prototype:

functiondeleteByValue(val) {
    for(var f in fruits) {
        if(fruits.hasOwnProperty(f) && fruits[f] == val) {
            delete fruits[f];
        }
    }
}

Solution 2:

var key = null;
for (var k in fruits){
  if (fruits[k] === 'apple'){
    key = k;
    break;
  }
}
if (key != null)
  delete fruits[key];

Iterate over the object finding the corresponding key, then remove it (if found).

Solution 3:

Don't know if this is efficient in terms of processing but using filter you can get this done in three lines:

var fruits = {
    "red" : "apple",
    "blue" : "blueberry",
    "yellow" : "banana"
}

var appleless_keys = Object.keys(fruits).filter(this_fruit => fruits[this_fruit] !== "apple");
appleless_obj = {};
appleless_keys.forEach(key => appleless_obj[key] = fruits[key]);
console.dir(appleless_obj);

Or as a function:

var fruits = {
    "red" : "apple",
    "blue" : "blueberry",
    "yellow" : "banana"
}

functionremove_fruit(fruit_to_remove,fruits){
  var new_keys = Object.keys(fruits).filter(this_fruit => fruits[this_fruit] !== fruit_to_remove);
  new_obj = {};
  new_keys.forEach(key => new_obj[key] = fruits[key]);  
  return new_obj;
}

console.dir(remove_fruit("apple",fruits));

Solution 4:

what about this one?

functiondelteByValue(a){
  fruits.foreach( function( k, v ) {
    if (fruits[v] == a){
      delete fruits[k];
    }
  });
}

Solution 5:

I think its a good idea to create a function and override the Object.prototype:

/**
 *  @autor Javier Cobos
 *  @param value The value to look for
 *  @return true if founded deleted, false if not
 */        
Object.prototype.removeByValue = function(value){
         var i;
         for(i inthis){
            if(this.hasOwnProperty(i))
                if(value === this[i]){
                   delete(this[i]);
                   returntrue;
                }
         }   
         returnfalse;
        }

// Examplevar fruits = {
        "red" : "apple",
        "blue" : "blueberry",
        "yellow" : "banana"
    }

        fruits .removeByValue("apple");

This way we have a new method for every single Object in our script :)