I have a string, for example: dashboard/12398911/overzicht and I want to check that string for 2 values. For dashboard and overzicht. If the first check is false, then the second check doesn't need to happen.

This is my current code:

private pageTypes = ['dashboard', 'klantenkaart', 'complexkaart', 'objectkaart', 'collegakaart'];
private subTypes = ['overzicht', 'tijdlijn', 'contracten', 'financieel', 'mededelingen'];

private isOnPageWithFilter(currentUrl: string): boolean {
    for (const pageType of this.pageTypes) {
        if (currentUrl.includes(pageType)) {
            for (const subType of this.subTypes) {
                if (currentUrl.includes(subType)) {
                    return true;
    return false;

I was wondering if there's a way of doing this where I don't need a nested for loop.

Plunkr: https://plnkr.co/edit/FXhbCr9aaXcL61g3q7Fe?p=preview

  • \$\begingroup\$ split your string using the delimiter / then check the index 0 and the index 2? \$\endgroup\$
    – IEatBagels
    Commented Oct 22, 2019 at 13:41

1 Answer 1


You can simplify it by using Array.prototype.some method and lazy evaluation of && operator

const pageTypes = ['dashboard', 'klantenkaart', 'complexkaart', 'objectkaart', 'collegakaart'];
const subTypes = ['overzicht', 'tijdlijn', 'contracten', 'financieel', 'mededelingen'];

function isOnPageWithFilter(currentUrl) {
    return pageTypes.some(x => currentUrl.includes(x)) && subTypes.some(x => currentUrl.includes(x));

console.log(isOnPageWithFilter('foobar.com?dashboard')); // false
console.log(isOnPageWithFilter('foobar.com?dashboard&overzicht')); // true

  • \$\begingroup\$ Wouldn't this return true for eenfinancieelramp#onwilligeklantenkaartoon? (How do I check lazy evaluation?) \$\endgroup\$
    – greybeard
    Commented Nov 1, 2019 at 7:02
  • \$\begingroup\$ In JavaScript (and many other languages) logical operators (&&,||) are evaluated lazily. This means that if first part of expression a && b, that is a, is evaluated to false then whole expression is false and there is no need to evaluate b \$\endgroup\$
    – purple
    Commented Nov 2, 2019 at 8:40

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