考虑:

http://example.com/page.html?returnurl=%2Fadmin

对于page.html内的js,它如何检索GET参数?

对于上面的简单例子,func('returnurl')应该是/admin。

但它也应该适用于复杂的查询字符串…


当前回答

这个函数使用正则表达式,如果参数不存在或没有任何值,则返回null:

function getQuery(q) {
   return (window.location.search.match(new RegExp('[?&]' + q + '=([^&]+)')) || [, null])[1];
}

其他回答

var getQueryParam = function(param) {
    var found;
    window.location.search.substr(1).split("&").forEach(function(item) {
        if (param ==  item.split("=")[0]) {
            found = item.split("=")[1];
        }
    });
    return found;
};

用窗户。位置的对象。这段代码提供了不带问号的GET。

window.location.search.substr(1)

在您的示例中,它将返回returnurl=%2Fadmin

编辑:我擅自改变了Qwerty的答案,这真的很好,正如他指出的那样,我完全按照OP的要求做了:

function findGetParameter(parameterName) {
    var result = null,
        tmp = [];
    location.search
        .substr(1)
        .split("&")
        .forEach(function (item) {
          tmp = item.split("=");
          if (tmp[0] === parameterName) result = decodeURIComponent(tmp[1]);
        });
    return result;
}

我从他的代码中删除了重复的函数执行,替换为一个变量(tmp),还添加了decodeURIComponent,完全符合OP的要求。我不确定这是不是安全问题。

或者使用普通的for循环,即使在IE8中也能工作:

function findGetParameter(parameterName) {
    var result = null,
        tmp = [];
    var items = location.search.substr(1).split("&");
    for (var index = 0; index < items.length; index++) {
        tmp = items[index].split("=");
        if (tmp[0] === parameterName) result = decodeURIComponent(tmp[1]);
    }
    return result;
}

我创建了一个简单的JavaScript函数来从URL访问GET参数。

只要包含这个JavaScript源代码,就可以访问get参数。 例如:在http://example.com/index.php?language=french中,语言变量可以通过$_GET["language"]访问。类似地,所有参数的列表将作为数组存储在变量$_GET_Params中。JavaScript和HTML都在下面的代码片段中提供:

<!DOCTYPE html> <html> <body> <!-- This script is required --> <script> function $_GET() { // Get the Full href of the page e.g. http://www.google.com/files/script.php?v=1.8.7&country=india var href = window.location.href; // Get the protocol e.g. http var protocol = window.location.protocol + "//"; // Get the host name e.g. www.google.com var hostname = window.location.hostname; // Get the pathname e.g. /files/script.php var pathname = window.location.pathname; // Remove protocol part var queries = href.replace(protocol, ''); // Remove host part queries = queries.replace(hostname, ''); // Remove pathname part queries = queries.replace(pathname, ''); // Presently, what is left in the variable queries is : ?v=1.8.7&country=india // Perform query functions if present if (queries != "" && queries != "?") { // Remove question mark '?' queries = queries.slice(1); // Split all the different queries queries = queries.split("&"); // Get the number of queries var length = queries.length; // Declare global variables to store keys and elements $_GET_Params = new Array(); $_GET = {}; // Perform functions per query for (var i = 0; i < length; i++) { // Get the present query var key = queries[i]; // Split the query and the value key = key.split("="); // Assign value to the $_GET variable $_GET[key[0]] = [key[1]]; // Assign value to the $_GET_Params variable $_GET_Params[i] = key[0]; } } } // Execute the function $_GET(); </script> <h1>GET Parameters</h1> <h2>Try to insert some get parameter and access it through JavaScript</h2> </body> </html>

dr解决方案在一行代码上使用普通JavaScript

var queryDict = {}
location.search.substr(1).split("&").forEach(function(item) {queryDict[item.split("=")[0]] = item.split("=")[1]})

这是最简单的解决方案。不幸的是,它不能处理多值键和编码字符。

"?a=1&a=%2Fadmin&b=2&c=3&d&e"
> queryDict
a: "%2Fadmin"  // Overridden with the last value, not decoded.
b: "2"
c: "3"
d: undefined
e: undefined

多值键和编码字符?

请参阅如何在JavaScript中获得查询字符串值的原始答案。

"?a=1&b=2&c=3&d&e&a=5&a=t%20e%20x%20t&e=http%3A%2F%2Fw3schools.com%2Fmy%20test.asp%3Fname%3Dståle%26car%3Dsaab&a=%2Fadmin"
> queryDict
a: ["1", "5", "t e x t", "/admin"]
b: ["2"]
c: ["3"]
d: [undefined]
e: [undefined, "http://w3schools.com/my test.asp?name=ståle&car=saab"]

在你的例子中,你可以像这样访问这个值:

"?returnurl=%2Fadmin"
> qd.returnurl    // ["/admin"]
> qd['returnurl'] // ["/admin"]
> qd.returnurl[0] // "/admin"

一种更花哨的方法::)

var options = window.location.search.slice(1)
                      .split('&')
                      .reduce(function _reduce (/*Object*/ a, /*String*/ b) {
                        b = b.split('=');
                        a[b[0]] = decodeURIComponent(b[1]);
                        return a;
                      }, {});