Remove array element based on object property

Question

I have an array of objects like so:

var myArray = [
    {field: 'id', operator: 'eq', value: id}, 
    {field: 'cStatus', operator: 'eq', value: cStatus}, 
    {field: 'money', operator: 'eq', value: money}
];

How do I remove a specific one based on its property?

e.g. How would I remove the array object with 'money' as the field property?

Answer 1

One possibility:

myArray = myArray.filter(function( obj ) {
    return obj.field !== 'money';
});

Please note that filter creates a new array. Any other variables referring to the original array would not get the filtered data although you update your original variable myArray with the new reference. Use with caution.

Answer 2

Iterate through the array, and splice out the ones you don't want. For easier use, iterate backwards so you don't have to take into account the live nature of the array:

for (var i = myArray.length - 1; i >= 0; --i) {
    if (myArray[i].field == "money") {
        myArray.splice(i,1);
    }
}

Answer 3

Say you want to remove the second object by its field property.

With ES6 it's as easy as this.

myArray.splice(myArray.findIndex(item => item.field === "cStatus"), 1)

Answer 4

In ES6, just one line.

const arr = arr.filter(item => item.key !== "some value");

:)

Answer 5

You can use lodash's findIndex to get the index of the specific element and then splice using it.

myArray.splice(_.findIndex(myArray, function(item) {
    return item.value === 'money';
}), 1);

Update

You can also use ES6's findIndex()

The findIndex() method returns the index of the first element in the array that satisfies the provided testing function. Otherwise -1 is returned.

const itemToRemoveIndex = myArray.findIndex(function(item) {
  return item.field === 'money';
});

// proceed to remove an item only if it exists.
if(itemToRemoveIndex !== -1){
  myArray.splice(itemToRemoveIndex, 1);
}

Answer 6

We can remove the element based on the property using the below 2 approaches.

1. Using filter method

testArray.filter(prop => prop.key !== 'Test Value')

2. Using splice method. For this method we need to find the index of the propery.

const index = testArray.findIndex(prop => prop.key === 'Test Value')
testArray.splice(index,1)

Answer 7

Here's another option using jQuery grep. Pass true as the third parameter to ensure grep removes items that match your function.

users = $.grep(users, function(el, idx) {return el.field == "money"}, true)

If you're already using jQuery then no shim is required, which is could be useful as opposed to using Array.filter.

Answer 8

var myArray = [
    {field: 'id', operator: 'eq', value: id}, 
    {field: 'cStatus', operator: 'eq', value: cStatus}, 
    {field: 'money', operator: 'eq', value: money}
];
console.log(myArray.length); //3
myArray = $.grep(myArray, function(element, index){return element.field == "money"}, true);
console.log(myArray.length); //2

Element is an object in the array. 3rd parameter true means will return an array of elements which fails your function logic, false means will return an array of elements which fails your function logic.

Answer 9

Using the lodash library:

var myArray = [
    {field: 'id', operator: 'eq', value: 'id'}, 
    {field: 'cStatus', operator: 'eq', value: 'cStatus'}, 
    {field: 'money', operator: 'eq', value: 'money'}
];
var newArray = _.remove(myArray, function(n) {
  return n.value === 'money';;
});
console.log('Array');
console.log(myArray);
console.log('New Array');
console.log(newArray);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.js"></script>

Answer 10

Based on some comments above below is the code how to remove an object based on a key name and key value

 var items = [ 
  { "id": 3.1, "name": "test 3.1"}, 
  { "id": 22, "name": "test 3.1" }, 
  { "id": 23, "name": "changed test 23" } 
  ]

    function removeByKey(array, params){
      array.some(function(item, index) {
        return (array[index][params.key] === params.value) ? !!(array.splice(index, 1)) : false;
      });
      return array;
    }

    var removed = removeByKey(items, {
      key: 'id',
      value: 23
    });

    console.log(removed);

Answer 11

jAndy's solution is probably best, but if you can't rely on filter you could do something like:

var myArray = [
    {field: 'id', operator: 'eq', value: 'id'}, 
    {field: 'cStatus', operator: 'eq', value: 'cStatus'}, 
    {field: 'money', operator: 'eq', value: "money"}
];

myArray.remove_key = function(key){
    var i = 0, 
        keyval = null;
    for( ; i < this.length; i++){
        if(this[i].field == key){
            keyval = this.splice(i, 1);
            break;
        }
    }
    return keyval;
}

Answer 12

Following is the code if you are not using jQuery. Demo

var myArray = [
    {field: 'id', operator: 'eq', value: 'id'}, 
    {field: 'cStatus', operator: 'eq', value: 'cStatus'}, 
    {field: 'money', operator: 'eq', value: 'money'}
];

alert(myArray.length);

for(var i=0 ; i<myArray.length; i++)
{
    if(myArray[i].value=='money')
        myArray.splice(i);
}

alert(myArray.length);

You can also use underscore library which have lots of function.

Underscore is a utility-belt library for JavaScript that provides a lot of the functional programming support