JavaScriptで文字列のURLからドメイン名とか取得するとき

const url = 'https://example.com/piyo/?hoge=foo'
const domain = new URL(url).origin

console.log(domain) // https://example.com

console.log(location.origin) // https://example.com

const url = new URL('https://example.com/piyo/puni.js?hoo=foo')

console.log(url.host)     // "example.com"
console.log(url.hostname) // "example.com"
console.log(url.href)     // "https://example.com/piyo/puni.js?hoge=foo"
console.log(url.origin)   // "https://example.com"
console.log(url.pathname) // "/piyo/puni.js"
console.log(url.protocol) // "https:"
console.log(url.search)   // "?hoge=foo"

// もうパラメータを取得するためにこんなことしなくていいんだね🥺
const url = 'https://example.com/piyo/puni.js?hoge=hoo'
console.log(url.substring(url.indexOf('?'))) // "?hoge=foo"