Standard Library Utilities

URL Parameters

Read query parameters with URLSearchParams.

url-params `URLSearchParams` parses query-string text into named values. It avoids manual splitting when code needs one parameter by name.

URL Parameters

limit
url_params.js
Replay: real traced execution (multi-file project)
const limit = "10";
const query = "limit=" + limit + "&sort=name";
const params = new URLSearchParams(query);
const parsedLimit = params.get("limit");
const sort = params.get("sort");

console.log("query=" + query);
console.log("limit=" + parsedLimit);
console.log("sort=" + sort);

const limit = "5";
const query = "limit=" + limit + "&sort=name";
const params = new URLSearchParams(query);
const parsedLimit = params.get("limit");
const sort = params.get("sort");

console.log("query=" + query);
console.log("limit=" + parsedLimit);
console.log("sort=" + sort);

const limit = "20";
const query = "limit=" + limit + "&sort=name";
const params = new URLSearchParams(query);
const parsedLimit = params.get("limit");
const sort = params.get("sort");

console.log("query=" + query);
console.log("limit=" + parsedLimit);
console.log("sort=" + sort);

  1. limit ← 10, query ← limit=10&sort=name, params ← limit=10&sort=name

    1const limit→ 10 = "10"; //@limit="5", "20"2const query→ limit=10&sort=name = "limit=" + limit→ 10 + "&sort=name";3const params→ limit=10&sort=name = new URLSearchParams(querylimit=10&sort=name);4const parsedLimit→ 10 = paramslimit=10&sort=name.get("limit");5const sort→ name = paramslimit=10&sort=name.get("sort");67console.log("query=" + querylimit=10&sort=name);8console.log("limit=" + parsedLimit10);9console.log("sort=" + sortname);
    outputquery=limit=10&sort=name
limit=10
sort=name

  1. limit ← 5, query ← limit=5&sort=name, params ← limit=5&sort=name

    1const limit→ 5 = "5";2const query→ limit=5&sort=name = "limit=" + limit→ 5 + "&sort=name";3const params→ limit=5&sort=name = new URLSearchParams(querylimit=5&sort=name);4const parsedLimit→ 5 = paramslimit=5&sort=name.get("limit");5const sort→ name = paramslimit=5&sort=name.get("sort");67console.log("query=" + querylimit=5&sort=name);8console.log("limit=" + parsedLimit5);9console.log("sort=" + sortname);
    outputquery=limit=5&sort=name
limit=5
sort=name

  1. limit ← 20, query ← limit=20&sort=name, params ← limit=20&sort=name

    1const limit→ 20 = "20";2const query→ limit=20&sort=name = "limit=" + limit→ 20 + "&sort=name";3const params→ limit=20&sort=name = new URLSearchParams(querylimit=20&sort=name);4const parsedLimit→ 20 = paramslimit=20&sort=name.get("limit");5const sort→ name = paramslimit=20&sort=name.get("sort");67console.log("query=" + querylimit=20&sort=name);8console.log("limit=" + parsedLimit20);9console.log("sort=" + sortname);
    outputquery=limit=20&sort=name
limit=20
sort=name