Node.js — URL

Import URL Module

const { URL } = require('url');

Creating URLs

const url = new URL('https://example.com:8080/path?q=search#hash');

url.protocol    // 'https:'
url.hostname    // 'example.com'
url.port        // '8080'
url.pathname    // '/path'
url.search      // '?q=search'
url.hash        // '#hash'
url.origin      // 'https://example.com:8080'

URL Search Params

const url = new URL('https://example.com?name=john&age=30');

url.searchParams.get('name')     // 'john'
url.searchParams.get('age')      // '30'

url.searchParams.set('city', 'NYC');
url.searchParams.append('hobby', 'reading');
url.searchParams.delete('age');

// Iterate params
url.searchParams.forEach((value, key) => {
    console.log(`${key}: ${value}`);
});

URL Parsing

const parsed = new URL('https://user:pass@example.com/path?q=1');

parsed.username   // 'user'
parsed.password   // 'pass'
parsed.host       // 'example.com'
parsed.pathname   // '/path'

Practical Example

function buildUrl(base, params) {
    const url = new URL(base);
    Object.entries(params).forEach(([key, val]) => {
        url.searchParams.set(key, val);
    });
    return url.toString();
}

buildUrl('https://api.example.com/users', { page: 1, limit: 10 });

Mini Practice

1. Parse a URL string
2. Access URL components
3. Manipulate search params
4. Build a URL with parameters

Up Next

Continue with Events — event-driven programming.