获取 URL GET 参数

getParam.js

function getParam(paramName, defaultValue = '')
{
    let url = location.search;
    let params = new Object();

    if (url.indexOf('?') != -1) {
        url = url.slice(1);
        strs = url.split('&');

        strs.forEach(function (str) {
            let keyValue = str.split('=');
            params[keyValue[0]] = decodeURI(keyValue[1]);
        });
    }

    return params[paramName] ? params[paramName] : defaultValue;
}