What is URLSearchParams?

URLSearchParams is a built-in JavaScript interface that makes it easy to work with the query string of a URL.

A query string is the part of a URL that comes after the “?” and contains key-value pairs.

Example URL:

https://example.com/page?customerId=123&status=active

Query string:

customerId=123&status=active

Why Use URLSearchParams?

It helps you:

• Read values from the URL
• Get specific query parameters (e.g., customerId)
• Add, update, or delete query parameters
• Convert query parameters back to a string

It replaces the old manual method of splitting URL strings.

How to Read Query Parameters

Step 1: Get the search/query part

const urlParams = new URLSearchParams(window.location.search);

window.location.search returns:

?customerId=123&status=active

Step 2: Get a value

const cusId = urlParams.get('customerId');
console.log(cusId);  // Output: 123

Another example:

const status = urlParams.get('status');
console.log(status);  // Output: active

Check if a parameter exists

if (urlParams.has('customerId')) {
    console.log("Customer ID is available");
}

Loop through all query parameters

for (const [key, value] of urlParams) {
    console.log(key, value);
}

Add or Update a Parameter

urlParams.set('page', 2);
console.log(urlParams.toString()); 
// customerId=123&status=active&page=2

Delete a Parameter

urlParams.delete('status');
console.log(urlParams.toString()); 
// customerId=123

Create a New URL with Modified Parameters

const newUrl = window.location.pathname + '?' + urlParams.toString();
console.log(newUrl);

Use Case: Passing Customer ID From Suitelet to HTML

Suitelet passes a URL like:

https://.../page.html?customerId=5678

Your HTML/JS retrieves it:

const urlParams = new URLSearchParams(window.location.search);
const cusId = urlParams.get('customerId');

console.log('Customer ID:', cusId);

Summary

URLSearchParams is the simplest and cleanest way to handle URL parameters in JavaScript. It helps you read, modify, and manage query strings without manually parsing them.