Cannot query array param from url

May 9, 2022

How to find the param whose key is an array using URLSearchParams?

// Browser url:
const url = http://localhost:4000/leads?status%5B0%5D=1&page=2;

// What my code does:
const urlParams = new URLSearchParams(window.location.search);
const myParam = (urlParams.get('status%5B0%5D') || urlParams.get(key)) || "";

// Let's focus on the below myParam:
urlParams.get('status%5B0%5D') // or
urlParams.get('status[]') // or
urlParams.has('status%5B0%5D') // or
urlParams.has('status[]') // or
urlParams.getAll('status%5B0%5D') // or
urlParams.getAll('status[]')

…has nothing useful. The aim is to delete a key from the url. Keys can be a string, status or an array, status%5B0%5D. I’m writing a function that can find the key whether it’s a string or an array. How comes whatever I do has no impact? Am I missing something?

I’ve looked at the below and nothing works:

// Copyright (c) Microsoft Corporation. All rights reserved.
// ...

interface URLSearchParams {
    /** Appends a specified key/value pair as a new search parameter. */
    append(name: string, value: string): void;
    /** Deletes the given search parameter, and its associated value, from the list of all search parameters. */
    delete(name: string): void;
    /** Returns the first value associated to the given search parameter. */
    get(name: string): string | null;
    /** Returns all the values association with a given search parameter. */
    getAll(name: string): string[];
    /** Returns a Boolean indicating if such a search parameter exists. */
    has(name: string): boolean;
    /** Sets the value associated to a given search parameter to the given value. If there were several values, delete the others. */
    set(name: string, value: string): void;
    sort(): void;
    /** Returns a string containing a query string suitable for use in a URL. Does not include the question mark. */
    toString(): string;
    forEach(callbackfn: (value: string, key: string, parent: URLSearchParams) => void, thisArg?: any): void;
}

>Solution :

Looks like you’ve got to decode the URI before using it

var url = new URL(decodeURI('http://localhost:4000/leads?status%5B0%5D=1&page=2;'));

console.log(url.search);
// '?status[0]=1&page=2;'

console.log(url.searchParams.get('status[0]'))
// '1'

console.log(url.searchParams.getAll('status[0]'))
// ['1']

Array.from(url.searchParams.entries()).forEach( console.log )
// ['status[0]', '1']
// ['page', '2;']