• 动态引入方法

function loadScript(url, callback) {
    var script = document.createElement("script");
    script.type = "text/javascript";
    if (typeof(callback) != "undefined") {
        if (script.readyState) {
            script.onreadystatechange = function() {
                if (script.readyState == "loaded" || script.readyState == "complete") {
                    script.onreadystatechange = null;
                    callback();
                }
            };
        } else {
            script.onload = function() {
                callback();
            };
        }
    };
    script.src = url;
    document.body.appendChild(script);
}

• 使用

loadScript("https://cdn.jsdelivr.net/npm/vue/dist/vue.js", function() { 
    alert('动态引入vue成功')
});