Remove elements from javascript array by position

Question

I have a javascript array

var countries = ["India","USA","China","Canada","China"];

I want to remove "China" only from 2nd position, and return

var countries = ["India","USA","Canada","China"];

Something similar to java linkedlist.remove(index)

I have read following question but I don't know how to use it if there are duplicate elements in array. How do I remove a particular element from an array in JavaScript?

@InvernoMuto I am not sure whether I can use array.splice in this situation. — Pradip Shenolkar, Apr 15 '15 at 16:59
You are Right, before to call splice you have to locate your "China" recurrence, you can use IndexOf otherwise LastIndexOf otherwise you havee to craft a custom IndexFilter — alessandro, Apr 15 '15 at 17:01
you can definitely use str.indexOf(searchValue[, fromIndex]) where fromIndex is the starting recurrence of your value — alessandro, Apr 15 '15 at 17:03
So many answers, not of which does what asked for. See my answer, it does exactly what you asked for — Sam Battat, Apr 15 '15 at 17:11

score 2 · Accepted Answer · 2015-04-15T17:05:09.133

2

Try splice():

countries.splice(2,1);

Here, first argument is the position and second is the number of elements to remove.

To get the index use indexOf(), -1 if not found:

countries.indexOf("China");

So you have:

var i = countries.indexOf("China");
if(-1 !== i) {
    countries.splice(i, 1);
}

edited Apr 15 '15 at 17:05

answered Apr 15 '15 at 16:58

score 1 · Answer 2 · edited May 23 '17 at 12:34

1

You can use a mix of array.indexOf and array.splice.

var countries = ["India","USA","China","Canada","China"];
var first_china = countries.indexOf("China");

if(first_china > -1){
    countries.splice(first_china , 1);
}

The question you linked also has the same answer (https://stackoverflow.com/a/5767357). indexOf will return you the index of the first match it finds. So if there are duplicates, it will still only remove the first one.

edited May 23 '17 at 12:34

Community

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answered Apr 15 '15 at 16:58

Rocket Hazmat

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this will remove first element not the last – Sky Walker Apr 15 '15 at 17:00

score 0 · Answer 3 · edited Apr 15 '15 at 17:06

0

You can use the JavaScript Array splice() Method.

var countries = ["India", "USA", "China", "Canada", "China"];
document.getElementById("demo").innerHTML = countries;

function myFunction() {
  countries.splice(2, 1);
  document.getElementById("demo").innerHTML = countries;
}

<button onclick="myFunction()">SPLICE!</button>
<p id="demo"></p>

edited Apr 15 '15 at 17:06

Rocket Hazmat

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answered Apr 15 '15 at 17:02

Ashesh

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score 0 · Answer 4 · answered Apr 15 '15 at 17:12

0

var c = ["India","USA","China","Canada","China"];
// provide the index you want to remove here (2)
var c2 = c.filter(function(item, idx) {if(idx != 2) return item;});

console.log(c2);

DEMO: http://jsfiddle.net/kf8epwnh/

answered Apr 15 '15 at 17:12

Sam Battat

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Remove elements from javascript array by position

4 Answers4