why javascript contains property is not working in chrome browser?

Question

Why javascript contains property is not working in chrome browser? I have tried that Contains Property in javascript.It is working fine in Mozila Firefox Browser. But It is

Answer 1

Use your own contains method and override firefox's contains() method. Because this method is widely used I mean -> (indexof).

String.prototype.contains = function(str) { return this.indexOf(str) != -1; };

Answer 2

You must understand why contains is not working. Actually there are two methods contains and includes and both have different usage.

contains :

The contains() method returns a Boolean value indicating whether a node is a descendant of a specified node.

A descendant can be a child, grandchild, great-grandchild, and so on.

var span = document.getElementById("mySPAN");
var div = document.getElementById("myDIV").contains(span);

The result of div will be:

true

please find jsfiddle

includes :

Check if a string includes with "world":

var str = "Hello world, welcome to the universe.";
var n = str.includes("world");

The result of n will be:

true

Definition and Usage

The includes() method determines whether a string contains the characters of a specified string.

This method returns true if the string contains the characters, and false if not.

Note: The includes() method is case sensitive.

Please find jsfiddle

And finally ofcourse you can also use indexOf method to achive same output

var ClearFilterValue = 'family Schools';
alert(ClearFilterValue.indexOf("family") != -1);

Hope this make sense

Answer 3

contains is not supported in Chrome, but you could use a polyfill:

if (!String.prototype.contains) {
    String.prototype.contains = function(s) {
        return this.indexOf(s) > -1
    }
}
'potato'.contains('tat') // true
'potato'.contains('tot') // false

Answer 4

indexof returns the position of the string. If not found, it will return -1:

var ClearFilterValue = 'family Schools';
alert(ClearFilterValue.indexOf("family") != -1);

Answer 5

I think you should be using indexOf

var ClearFilterValue = 'family Schools';
if(ClearFilterValue.indexOf("family") !== -1) {
      alert('Success');
}

Also not sure if you should be making a polyfill as pretty much no browser seems to support it anyways https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/contains

None of IE's support it, Chrome apparently starting at 30, FF starting at 19, and i doubt mobile browsers support it either

Answer 6

Actually String.contains is not supported in Chrome as per the MDN

Here's the way to resolve the issue:

Polyfill

You can easily polyfill this method :

if (!('contains' in String.prototype)) String.prototype.contains = function (str, startIndex) {
    return -1 !== String.prototype.indexOf.call(this, str, startIndex);
};

var ClearFilterValue = 'family Schools';
if (ClearFilterValue.contains("family") == true) {
    alert('Success');
}

Demo: Fiddle