Why isn't my URL string being shortened as expected?

Question

I have a variable named siteURL which is set using window.location.href.

I'm wanting to trim off the the last 10 characters which in this case is ...index.html.

var siteURL = window.location.href;

if (siteURL.endsWith('index.html')) {
   siteURL.substring(0, siteURL.length - 10);
}

//log the output
console.log(siteURL);

I'm trying this but it doesn't seem to be removing the last 10 character. Does anyone know where I'm going wrong and could point me in the right direction?

JavaScript is case sensitive so you made up a variable name. Also you need to assign the substring to the variable. Strings are primitives and are passed around as copies (not modified in place). — Dominic, May 13 '19 at 15:47

Shidersz · Accepted Answer · 2019-05-13T16:00:28.520

You need to store the returned value of String.substring() back in siteUrl variable. Note also that strings are inmutables on Javascript (Check next reference too: Are JavaScript strings immutable? Do I need a "string builder" in JavaScript?).

var siteURL = "some/url/with/index.html";

if (siteURL.endsWith('index.html'))
{
   siteURL = siteURL.substring(0, siteURL.length - 10);
}

console.log(siteURL);

.as-console {background-color:black !important; color:lime;}
.as-console-wrapper {max-height:100% !important; top:0;}

However, a better approach for what you want to is to use String.replace() with a regular expression:

var siteURL = "some/url/with-index.html/index.html";
siteURL = siteURL.replace(/index\.html$/, "");
console.log(siteURL);

.as-console {background-color:black !important; color:lime;}
.as-console-wrapper {max-height:100% !important; top:0;}

You're a legend. That's exactly what I was trying to do. Thanks for including the link to string replace. Super handy! — finners, May 13 '19 at 16:01

score 1 · Answer 2 · answered May 13 '19 at 15:46

1

You're performing the action, you just need to actually assign the value.

siteURL = siteURL.substring(0, siteURL.length - 10);

answered May 13 '19 at 15:46

Caleb Davenport

613
5
18

score 1 · Answer 3 · answered May 13 '19 at 15:47

1

You can do:

var newStr = siteURL.substring(0, siteURL.length-10);

var newStr = siteURL.substr(0, siteURL.length-10);

var newStr = siteURL.slice(0, siteURL.length-10);

Any of them will work:

console.log(newStr);

answered May 13 '19 at 15:47

Evik Ghazarian

1,803
1
9
24

Why isn't my URL string being shortened as expected?

3 Answers3