JavaScript endsWith is not working in IEv10?

Question

I'm trying to compare two strings in JavaScript using endsWith(), like

var isValid = string1.endsWith(string2);

It's working fine in Google Chrome and Mozilla. When comes to IE it's throwing a console error as follows

SCRIPT438: Object doesn't support property or method 'endsWith'

How can I resolve it?

score 22 · Accepted Answer · edited Aug 22 '17 at 06:22

22

Method endsWith() not supported in IE. Check browser compatibility here.

You can use polyfill option taken from MDN documentation:

if (!String.prototype.endsWith) {
  String.prototype.endsWith = function(searchString, position) {
      var subjectString = this.toString();
      if (typeof position !== 'number' || !isFinite(position) 
          || Math.floor(position) !== position || position > subjectString.length) {
        position = subjectString.length;
      }
      position -= searchString.length;
      var lastIndex = subjectString.indexOf(searchString, position);
      return lastIndex !== -1 && lastIndex === position;
  };
}

edited Aug 22 '17 at 06:22

radbyx

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answered May 31 '16 at 11:25

Pranav C Balan

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It helps to know that this script can be placed anywhere. Ideally it is loaded as the page loads too so that it is made available to all other functions – David Brossard Aug 29 '17 at 14:26
Find the simplified answer here https://stackoverflow.com/questions/37544376/javascript-endswith-is-not-working-in-iev10#answer-37545037 – Sivaprasad derangula Nov 07 '17 at 05:10

Sivaprasad derangula · Answer 2 · 2016-06-01T11:19:42.240

18

I found the simplest answer,

All you need do is to define the prototype

 if (!String.prototype.endsWith) {
   String.prototype.endsWith = function(suffix) {
     return this.indexOf(suffix, this.length - suffix.length) !== -1;
   };
 }

edited Jun 01 '16 at 11:19

answered May 31 '16 at 11:53

Sivaprasad derangula

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Kudos. Anyway, I think `string.indexOf(suffix, string.length - suffix.length) !== -1;` is sufficient, since altering the prototype is a bad idea – Marco Sulla Feb 15 '23 at 10:31

score 2 · Answer 3 · edited May 23 '17 at 11:54

2

It's generally bad practise to extend the prototype of a native JavaScript object. See here - Why is extending native objects a bad practice?

You can use a simple check like this that will work cross-browser:

var isValid = (string1.lastIndexOf(string2) == (string1.length - string2.length))

edited May 23 '17 at 11:54

Community

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answered May 05 '17 at 03:48

Chris Halcrow

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This will fail basic test cases e.g `string1 = "a", string2 = "bc";` would return true – Drenai Aug 25 '18 at 12:27

score 0 · Answer 4 · edited Sep 04 '19 at 13:19

0

Reaction on an old issue: Elaborating on alternative for endsWith() in IE11.

To avoid that string1 = "a", string2 = "bc"; would return true:

var isValid = (string1.lastIndexOf(string2) == (string1.length - string2.length) && string1.lastIndexOf(string2) >= 0);

edited Sep 04 '19 at 13:19

Guillermo Cacheda

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answered Sep 04 '19 at 12:54

HansW

1

JavaScript endsWith is not working in IEv10?

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