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up vote 5215 down vote favorite
816

Usually, I would expect a String.contains() method, but there doesn't seem to be one. What is a reasonable way to check for this?

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11  
It's easy with the indexOf method, you can see a tutorial of indexOf and substring here: dreamsyssoft.com/javascript-shell-scripting/… – Triton Man Mar 30 '15 at 17:53
4  
possible duplicate of JQuery string contains check – Saswat Aug 18 '15 at 11:14
4  
you can see speed of r.indexOf(s) !== -1; fastest than others. hayageek.com/javascript-string-contains – Sherali Turdiyev Oct 1 '15 at 5:37
    
you can try this "foo bar".match('oo') ? console.log("contained") : console.log("not contained"); – Alejandro Vales May 24 at 10:51
    
Finally! There is an includes() method for strings in ECMA6. Supported by everyone except IE. A good polyfill is available in Mozilla's docs: developer.mozilla.org/en/docs/Web/JavaScript/Reference/… – K48 Oct 3 at 11:49

40 Answers 40

1 2
up vote 7 down vote

If you don't like the !!~, etc. tricks, you can simply add +1 to the result of .indexOf(). This way if a string is not found, -1 + 1 = 0 will be falsy, 0.. + 1 = 1.. will be truthy:

if ("StackOverflow".indexOf("Stack") + 1 )
    alert('contains');
else 
    alert('does not contain');
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3  
Unreadable for human being... – jmcollin92 Oct 5 '14 at 16:34
1  
I perfectly agree, and I don't use it myself, but readability wasn't in the question :) – biziclop Oct 6 '14 at 9:11
up vote 6 down vote

This is a function to check if a substring is existing in a string or not:

function isStringMatch(str, str_to_match) {
    return (str.indexOf(str_to_match) > -1);
}
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3  
Just a heads up... this should be either >=0, >-1, or (my preference) !== -1, as this will fail in its current form if the string begins with the substring. – Karl White Feb 1 '14 at 8:07
up vote 6 down vote

I know that best way is str.indexOf(s) !== -1; http://hayageek.com/javascript-string-contains/

I suggest another way(str.replace(s1, "") !== str):

var str = "Hello World!", s1 = "ello", s2 = "elloo";
alert(str.replace(s1, "") !== str);
alert(str.replace(s2, "") !== str);

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up vote 5 down vote

Try this:

if ('Hello, World!'.indexOf('orl') !== -1)
    alert("The string 'Hello World' contains the substring 'orl'!");
else
    alert("The string 'Hello World' does not contain the substring 'orl'!");

Here is an example: jsfiddle

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up vote 5 down vote

You can use indexOf which returns the position of the string. If not found, it will return -1. So if the method returns -1 string doesn't exist

var string = "This is a test string",
substring = "test";
if(string.indexOf(substring) >= 0)
  //substring exist
else
  //substring does not exist
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up vote 4 down vote

You can also do something like this

var snipers = " Vasily Zaytsev, Simo Hayha, Chris Kyle";
var me = "Josip";

function printSniperStatus (person) {
    if (aContainsB(snipers, person)) {
        console.log(person + " is a sniper.");
    } else {
        console.log(person + " is NOT a sniper.");
    }
}

// Outputs: "Josip is NOT a sniper."
printSniperStatus(me);
share|improve this answer
    
Is aContainsB a standard javascript function? I found it to be a custom function here: adripofjavascript.com/blog/drips/…. The function itself is: function aContainsB (a, b) { return a.indexOf(b) >= 0; }. – Dov Miller Sep 15 at 12:24
up vote 3 down vote

One more Function search

var str = "stack Overflow";
var n = str.search("Overflow");
if(n != -1)
alert('String exists')
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1  
search is for regular expressions – Gothdo Dec 11 '15 at 18:30
up vote 2 down vote

There are multiple ways to do this. But most of the time, you will be fine using the indexOf() method. indexOf() returns the position of the string passed to it as argument and -1 if the string on which it was called doesn't contain the argument string.

var str = "A cat and a dog";
str.indexOf("cat"); // returns 2
str.indexOf("panda"); // returns -1
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up vote 0 down vote

With ECMAScript 2015, we can use includes()

let s = "foo";
console.log(s.includes("oo"));
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This is just repeating some of the existing answers. – Pang 17 hours ago
up vote -4 down vote 
result = 'GBP|1800';
//if pipe delimeter is there it returns true else false.
if(result.indexOf("|"))
{
    console.log('go default:' +result);
    var cur = result.substring(0, 3);//returns GBP
    console.log('go default cur:' +cur);
    var minmum_fee = result.substring(4);//gets the substring amount
    console.log('go default minmum_fee:' +minmum_fee);

}
else
{
    console.log('not found:' +result);
}
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1 2

protected by Sean Vieira Nov 2 '12 at 12:31

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