Javascript常用函数

获取URL参数（支持中文）

    function getQueryString(name) {
        let reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
        let r = window.location.search.substr(1).match(reg);
        if (r != null) {
            return decodeURIComponent(r[2]);
        };
        return null;
    }

JQuery请求JSON

    function queryJson(url, successful, fail, error) {
        $.ajax({
            type: "GET",
            url: url,
            dataType: "json",
            success: function (json) {
                if ("code" in json && "noerror" != json.code) {
                    if (null != fail) {
                        fail(json);
                    }
                }
                else {
                    if (null != successful) {
                        successful(json);
                    }
                }
            },
            error: function (jqxhr, textStatus, errorThrown) {
                if (null != error) {
                    error(textStatus);
                }
            }
        });
    }

JQuery请求TEXT

    function queryText(url, successful, fail, error) {
        $.ajax({
            type: "GET",
            url: url,
            dataType: "text",
            success: function (res) {
                if ("" == res) {
                    if (null != fail) {
                        fail(res);
                    }
                }
                else {
                    if (null == successful) {
                        successful(res);
                    }
                }
            },
            error: function (jqxhr, textStatus, errorThrown) {
                if (null != error) {
                    error(textStatus);
                }
            }
        });
    }

判断是不是为空字符串

    function isNull(val) {
        return null == val || undefined == val || "undefined" == val || "" == val;
    }