JS动态加载引入JS文件

1.调整标签位置
可以把<script>标签放到HTML文档的最后面，这样不影响页面加载。

 

2.动态创建script来加载

loadJS('js/index.min.js?V=1.0.0.1',function(){
    //加载,并执行回调函数
    //alert('动态引入js成功')
});

function loadJS(url, callback) {
    var script = document.createElement('script'), fn = callback || function() {
    };
    script.type = 'text/javascript';
    // IE
    if (script.readyState) {
        script.onreadystatechange = function() {
            if (script.readyState == 'loaded'
                    || script.readyState == 'complete') {
                script.onreadystatechange = null;
                fn();
            }
        };
    } else {
        // 其他浏览器
        script.onload = function() {
            fn();
        };
    }
    script.src = url;
    document.getElementsByTagName('head')[0].appendChild(script);
}

 

参考：
http://www.liushuishiyin.com/n/1340.html
http://www.javacui.com/javascript/568.html
https://www.jb51.net/article/139481.htm
https://www.jb51.net/article/139504.htm