javascript 获取 URL 参数的值

使用 URLSearchParams 可以快速获取到参数的值。

例子

const paramsString = 'q=URLUtils.searchParams&topic=api';
let searchParams = new URLSearchParams(paramsString);

//Iterate the search parameters.
for (let p of searchParams) {
  console.log(p);
}

searchParams.has('topic') === true;      // true
searchParams.get('topic') === "api";     // true
searchParams.getAll('topic');            // ["api"]
searchParams.get('foo') === null;        // true
searchParams.append('topic', 'webdev');
searchParams.toString();                 // "q=URLUtils.searchParams&topic=api&topic=webdev"
searchParams.set('topic', 'More webdev');
searchParams.toString();                 // "q=URLUtils.searchParams&topic=More+webdev"
searchParams.delete('topic');
searchParams.toString();                 // "q=URLUtils.searchParams"

获取请求 URL 的参数时

const queryString = window.location.search;
console.log(queryString);
// ?product=shirt&color=blue&newuser&size=m

const urlParams = new URLSearchParams(queryString);

const product = urlParams.get('product')
console.log(product);
// shirt

const color = urlParams.get('color')
console.log(color);
// blue

const newUser = urlParams.get('newuser')
console.log(newUser);
// empty string

console.log(urlParams.has('product'));
// true

console.log(urlParams.has('paymentmethod'));
// false

文章节选自：https://www.sitepoint.com/get-url-parameters-with-javascript/
文章节选自：https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams