Check if hostname is in an array with JS

Question

Why does this code doesn't work ? (it is part of a chrome extension),

I don't understand why using this method to check if the hostname of the current page is in the array ac_websites does not work.

I am not sure what window.location.hostname returns (string or something else)

Maybe indexOf() only works with strings.

const ac_websites = ["sciencedirect.com", "ncbi.nlm.nih.gov", "pubmed.ncbi.nlm.nih.gov", "ieeexplore.ieee.org", "ci.nii.ac.jp"]


chrome.runtime.onMessage.addListener(function (request) {
    const url = document.location.href
    const hostname = window.location.hostname
    
    if (ac_websites.indexOf(hostname) != 1) {
        window.open("https://google.com/" + url);
    } else {
        alert("Not an academic website")
    }
})

`hostname` returns a string. Maybe the hostname begins with `www.`? You don't have that in your `ac_websites` array. — Barmar, Apr 28 '21 at 17:08
Read [this article](https://ericlippert.com/2014/03/05/how-to-debug-small-programs/) for tips on debugging your code. — Code-Apprentice, Apr 28 '21 at 17:12

score 3 · Answer 1 · answered Apr 28 '21 at 17:10

3

You can also use Array.includes().

if (ac_websites.includes(hostname)) {
        window.open("https://google.com/" + url);
    } else {
        alert("Not an academic website")
    }

answered Apr 28 '21 at 17:10

Dipanshu Kumar Suman

373
2
13

1

No need to answer a typo question, even if this is good advice. Use a comment instead, please. – Apr 28 '21 at 17:12

Check if hostname is in an array with JS

1 Answers1