js获取url根

function getURLRoot() {
    var protocol = window.location.protocol;
    var hostname = window.location.hostname;
    var port = window.location.port ? ':' + window.location.port : '';
    return protocol + '//' + hostname + port;
}

console.log(getURLRoot()); // 输出例如 "http://www.example.com" 或 "https://www.example.com:8080"

function getURLRoot() {
    var url = new URL(window.location.href);
    return url.origin;
}

console.log(getURLRoot()); // 输出例如 "http://www.example.com" 或 "https://www.example.com:8080"

function getURLRoot() {
    var url = window.location.href;
    var match = /^https?:\/\/[^\/]+/.exec(url);
    return match ? match[0] : '';
}

console.log(getURLRoot()); // 输出例如 "http://www.example.com" 或 "https://www.example.com:8080"