ES6 filter an array with Regex

Question

I\'m trying to filter an array that contains a bunch of urls. I need to return the urls that only contain the word \"contact\".

For example there is a link htt

Answer 1

var links = ["https://www.example.com/v1/contact-us/ca", "https://www.example.com/v1/contact-us/sanjose", "https://www.example.com/v1/meeting-us/ca"];

var newlink = links.filter(function(link){
  return link.includes("contact")
});

console.log(newlink)

Try this. It should work.

Answer 2

const regex = new RegExp('/contact\\b', 'g');
const matchedSites = sites.links.filter(e => 
  regex.test(e.href));
console.log(matchedSites);

Answer 3

I realize that the question requests regex, but the sensible answer here is

someArray.filter(str => str.includes('contact'))

Answer 4

Firstly new RegExp('/\bcontact\b', 'g'); is equivalent to /\/@contact@/g where the @ are backspace character (ASCII 08) ... clearly not what you want

So, you would do new RegExp('/\\bcontact\\b', 'g'); - this is equivalent to /\/\bcontact\b/g

However, the \\b after / is redundant

so ... down to /\/contact\b/g

Using string.match here as regex.test is misused. Below is the description

var sites = { 
    links: [
        {href: 'https://www.example.com/v1/contact-us/ca'},
        {href: 'https://www.example.com/v1/contact-us/au'},
        {href: 'https://www.example.com/v1/contact-us/us'},
        {href: 'https://www.example.com/v1/dontcontact-us/us'}
    ]
};

const regex = new RegExp('/contact\\b', 'g');
const matchedSites = sites.links.filter(({href}) => href.match(regex));
console.log(matchedSites);

The next problem is using the ONE regex multiple times in a regexp.test with g flag. With each call, it will look from the next indexOf previous found substring and with consecutive calls on a same-type string, it basically will return true, false, true, false.

If you want to use regex.test, then don't re-use the same regex unless you know the consequences of doing so or do not use g flag (which here you do not need)

var sites = { 
    links: [
        {href: 'https://www.example.com/v1/contact-us/ca'},
        {href: 'https://www.example.com/v1/contact-us/au'},
        {href: 'https://www.example.com/v1/contact-us/us'},
        {href: 'https://www.example.com/v1/dontcontact-us/us'}
    ]
};

const regex = new RegExp('/contact\\b', 'g');
const correctRegex = new RegExp('/contact\\b');

const matchedSitesFailed = sites.links.filter(({href}) => regex.test(href));
const matchedSitesSuccess = sites.links.filter(({href}) => new RegExp('/contact\\b', 'g').test(href));
const matchedSitesSuccess2 = sites.links.filter(({href}) => correctRegex.test(href));

console.log('failed returns:', matchedSitesFailed.length);
console.log('success returns:', matchedSitesSuccess.length);
console.log('success returns 2:', matchedSitesSuccess2.length);

Answer 5

You need to return the truthy / falsy result from filter function.

const regex = new RegExp("/\b?contact\b?", 'g');

const sites = {
  links: [{
      href: 'http://www.some-site.com/contact-us'
    },
    {
      href: 'http://www.some-site.com/about'
    },
    {
      href: 'http://www.some-site.com/admin'
    }
  ]
}

const fitered = sites.links.filter((link) => {
  return link.href.match(regex);
});

console.log(fitered);