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Get query string values in JavaScript

Posted on | Post modified
取得參數的值

作法一

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function getParameterByName(name, url) {
    if (!url) url = window.location.href;
    name = name.replace(/[\[\]]/g, "\\$&");
    var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
        results = regex.exec(url);
    if (!results) return null;
    if (!results[2]) return '';
    return decodeURIComponent(results[2].replace(/\+/g, " "));
}

//Usage:
// query string: ?foo=lorem&bar=&baz
var foo = getParameterByName('foo'); // "lorem"
var bar = getParameterByName('bar'); // "" (present with empty value)
var baz = getParameterByName('baz'); // "" (present with no value)
var qux = getParameterByName('qux'); // null (absent)

其他學習

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var urlParams;
(window.onpopstate = function () {
    var match,
        pl     = /\+/g,  // Regex for replacing addition symbol with a space
        search = /([^&=]+)=?([^&]*)/g,
        decode = function (s) { return decodeURIComponent(s.replace(pl, " ")); },
        query  = window.location.search.substring(1);

    urlParams = {};
    while (match = search.exec(query))
       urlParams[decode(match[1])] = decode(match[2]);
})();
//
//Example querystring:
//?i=main&mode=front&sid=de8d49b78a85a322c4155015fdce22c4&enc=+Hello%20&empty
//
//Result: 
//  urlParams = {
//     enc: " Hello ",
//     i: "main",
//     mode: "front",
//     sid: "de8d49b78a85a322c4155015fdce22c4",
//     empty: ""
// }

// alert(urlParams["mode"]);
// // -> "front"

// alert("empty" in urlParams);
// // -> true
//  //}

Ref.

  1. How can I get query string values in JavaScript?