Remove Object from Array using JavaScript
Remove Object from Array using JavaScript
Question
How can I remove an object from an array?
I wish to remove the object that includes name Kristian
from someArray
. For example:
someArray = [{name:"Kristian", lines:"2,5,10"},
{name:"John", lines:"1,19,26,96"}];
I want to achieve:
someArray = [{name:"John", lines:"1,19,26,96"}];
Accepted Answer
You can use several methods to remove item(s) from an Array:
//1
someArray.shift(); // first element removed
//2
someArray = someArray.slice(1); // first element removed
//3
someArray.splice(0, 1); // first element removed
//4
someArray.pop(); // last element removed
//5
someArray = someArray.slice(0, a.length - 1); // last element removed
//6
someArray.length = someArray.length - 1; // last element removed
If you want to remove element at position x
, use:
someArray.splice(x, 1);
Or
someArray = someArray.slice(0, x).concat(someArray.slice(-x));
Reply to the comment of @chill182: you can remove one or more elements from an array using Array.filter
, or Array.splice
combined with Array.findIndex
(see MDN), e.g.
// non destructive filter > noJohn = John removed, but someArray will not change
let someArray = getArray();
let noJohn = someArray.filter( el => el.name !== "John" );
log("non destructive filter > noJohn = ", format(noJohn));
log(`**someArray.length ${someArray.length}`);
// destructive filter/reassign John removed > someArray2 =
let someArray2 = getArray();
someArray2 = someArray2.filter( el => el.name !== "John" );
log("", "destructive filter/reassign John removed > someArray2 =",
format(someArray2));
log(`**someArray2.length ${someArray2.length}`);
// destructive splice /w findIndex Brian remains > someArray3 =
let someArray3 = getArray();
someArray3.splice(someArray3.findIndex(v => v.name === "Kristian"), 1);
someArray3.splice(someArray3.findIndex(v => v.name === "John"), 1);
log("", "destructive splice /w findIndex Brian remains > someArray3 =",
format(someArray3));
log(`**someArray3.length ${someArray3.length}`);
// Note: if you're not sure about the contents of your array,
// you should check the results of findIndex first
let someArray4 = getArray();
const indx = someArray4.findIndex(v => v.name === "Michael");
someArray4.splice(indx, indx >= 0 ? 1 : 0);
log("", "check findIndex result first > someArray4 (nothing is removed) > ",
format(someArray4));
log(`**someArray4.length (should still be 3) ${someArray4.length}`);
function format(obj) {
return JSON.stringify(obj, null, " ");
}
function log(...txt) {
document.querySelector("pre").textContent += `${txt.join("\n")}\n`
}
function getArray() {
return [ {name: "Kristian", lines: "2,5,10"},
{name: "John", lines: "1,19,26,96"},
{name: "Brian", lines: "3,9,62,36"} ];
}
<pre>
**Results**
</pre>
Read more… Read less…
The clean solution would be to use Array.filter
:
var filtered = someArray.filter(function(el) { return el.Name != "Kristian"; });
The problem with this is that it does not work on IE < 9. However, you can include code from a Javascript library (e.g. underscore.js) that implements this for any browser.
I recommend using lodash.js or sugar.js for common tasks like this:
// lodash.js
someArray = _.reject(someArray, function(el) { return el.Name === "Kristian"; });
// sugar.js
someArray.remove(function(el) { return el.Name === "Kristian"; });
in most projects, having a set of helper methods that is provided by libraries like these is quite useful.
How about this?
$.each(someArray, function(i){
if(someArray[i].name === 'Kristian') {
someArray.splice(i,1);
return false;
}
});
Your "array" as shown is invalid JavaScript syntax. Curly brackets {}
are for objects with property name/value pairs, but square brackets []
are for arrays - like so:
someArray = [{name:"Kristian", lines:"2,5,10"}, {name:"John", lines:"1,19,26,96"}];
In that case, you can use the .splice()
method to remove an item. To remove the first item (index 0), say:
someArray.splice(0,1);
// someArray = [{name:"John", lines:"1,19,26,96"}];
If you don't know the index but want to search through the array to find the item with name "Kristian" to remove you could to this:
for (var i =0; i < someArray.length; i++)
if (someArray[i].name === "Kristian") {
someArray.splice(i,1);
break;
}
EDIT: I just noticed your question is tagged with "jQuery", so you could try the $.grep()
method:
someArray = $.grep(someArray,
function(o,i) { return o.name === "Kristian"; },
true);
ES2015
let someArray = [
{name:"Kristian", lines:"2,5,10"},
{name:"John", lines:"1,19,26,96"},
{name:"Kristian", lines:"2,58,160"},
{name:"Felix", lines:"1,19,26,96"}
];
someArray = someArray.filter(person => person.name != 'John');
It will remove John!