51

I want to know what location.search.substring(1) actually does. I saw this code on some website. I tried to print using alert, but this did not give any result. Is it supposed to alert location href?

alert(location.search.substring(1))
user151841
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jchand
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    location.search returns the query portion of a URL including the Question mark (?). This return a string and then we do substring operation on that string. substring(1) means return the string skipping the first character. I our case "the question mark". – anandharshan Dec 04 '18 at 06:59
  • https://www.w3schools.com/jsref/prop_loc_search.asp – frederj Oct 02 '19 at 21:24

7 Answers7

55
http://example.com/index.php?foo=bar

location.search
> ?foo=bar
location.search.substring(1)
> foo=bar

So that code will return the entire query parameters without the question mark.

sachleen
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21

The location.search property contains the query string of an URI (including the ?), if any.

Example:

http://www.example.org/index.php?param=arg
location.search is ?param=arg

So your code snips away the leading ? and returns param=arg.

Gregor
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    Your first sentence doesn't match your example - location.search _includes_ the ?. – Nick Jan 18 '13 at 08:41
16

The search property returns the query portion of a URL, including the question mark (?).

That means, that location.search.substring(1) should return the data without the question mark.

// http://www.example.com/index.html
console.log(location.search.substring(1)); // no query string, so displays nothing

// http://www.example.com/index.html?property=value
console.log(location.search.substring(1)); // should display "property=value"

The "query porpotion" is the query string:

http://www.example.com/?property=value&property2=value
                       |        query string         |
Tim S.
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7

e.g. if you have the following url

http://www.example.org/index.htm?Browser=Netscape

then window.location.search will return ?Browser=Netscape as a string

JuHwon
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  • I am trying to alert it like alert(window.location.search); I am writing some query string in the url and then click to see alert but it doesn't show any thing. The alert pops up but showing nothing. what could be causing that? – Shaonline Sep 29 '15 at 13:35
  • I would need an exact example of your url and query to reproduce your issue. Though u also could try the debug mode of your browser. set a breakpoint at the line you want and just type `window.location.search` or `window.location` in your console. Its a much better approach than alert to see whats goin on. – JuHwon Oct 01 '15 at 14:47
7

location.search returns a query string including the initial question mark. The substr method is to remove the initial question mark from the returned query string.

The reason why you're not getting any results in the alert() is because you're trying to read query string on a website which doesn't have any.

Here's how you test:

  1. Go to this URL
  2. Open up the console on your browser
  3. Paste the code snippet shared below and hit enter

var container = {};
location.search.split('&').toString().substr(1).split(",").forEach(item => {
    container[item.split("=")[0]] = decodeURIComponent(item.split("=")[1]) ?  item.split("=")[1]: "No query strings available" ;
});
console.log(container);

Old question but the answer might be helpful for new visitors on this page.

Rehan H
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1

It returns the query string, without the initial question mark. You'll only see a result if there's a query string on the page, e.g. http://www.example.com?parameter=value.

Nick
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1

Now is year of 2018, this is how you do it in 2018.

Sample URL:

http://localhost:10/mapserver1/viewer/?config=viewer_simple1&url=https://maps2.dcgis.dc.gov/dcgis/rest/services/Zoning/MapServer&zoom=17&lat=38.917292&long=-77.036420

My working code to extract each query parameter:

        var ___zoom;
        var ___lat;
        var ___long;
        var ___basemap;

        var ___type;
        var ___url;
        var ___title;
        var ___opacity;



        if ( location.search.match(/zoom=([^&]*)/i) )
        {
             ___zoom = location.search.match(/zoom=([^&]*)/i)[1];
         }

        if ( location.search.match(/lat=([^&]*)/i) )
        {
           ___lat = location.search.match(/lat=([^&]*)/i)[1];
        }

        if (location.search.match(/long=([^&]*)/i))
        {
            ___long = location.search.match(/long=([^&]*)/i)[1];
        }

        if (location.search.match(/basemap=([^&]*)/i))
        {
            ___basemap = location.search.match(/basemap=([^&]*)/i)[1];
        }

        if (location.search.match(/type=([^&]*)/i))
        {
            ___type = location.search.match(/type=([^&]*)/i)[1];
        }

       if (location.search.match(/url=([^&]*)/i))
        {
            ___url = location.search.match(/url=([^&]*)/i)[1];
        }


        if (location.search.match(/title=([^&]*)/i))
        {
            ___title = location.search.match(/title=([^&]*)/i)[1];
        }

        if (location.search.match(/opacity=([^&]*)/i))
        {
            ___opacity = location.search.match(/opacity=([^&]*)/i)[1];
        }


        //console.log(location.search.match(/zoom=([^&]*)/i)[0]);   //    'zoom=17'
        //console.log(location.search.match(/zoom=([^&]*)/i)[1]);   //     '17'
        console.log(___zoom); 
        console.log(___lat); 
        console.log(___long); 
        console.log(___basemap); 

        console.log(___type); 
        console.log(___url); 
        console.log(___title); 
        console.log(___opacity);
hoogw
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