【前端JS、JQ常用方法记录】

1. 【生成32位随机UUID】

function get_uuid() {
    var s = [];
    var hexDigits = "0123456789abcdef";
    for (var i = 0; i < 32; i++) {
        s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1);
    }
    s[14] = "3";
    s[19] = hexDigits.substr((s[19] & 0x3) | 0x8, 1);
    var uuid = s.join("");
    return uuid;
}

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2. 【从字符串中提取数字】

function getFloat(v) {
    if (typeof (v) == 'string') {
        var regEx = /[^\d|^\.|^\-]/g;
        return v.replace(regEx, '');
    }
}

PS:这个方法会提取字符串中所有数字，如getFloat('ASD789SDF213')的结果是789213

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3. 【浏览器标签页切回来触发事件】

      document.addEventListener('visibilitychange',function(){ //浏览器切换事件
            if(document.visibilityState!='hidden') {
              
              //todo

            }
        });

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4. 【自定义获取url中参数对应的值】

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

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5. 【JQ获取项目路径】

//获取服务器路径
function getWebRootPath(request) {
    if (!request) {
        request = "";
    }
    var a = window.document.location.href;//
    var b = window.document.location.pathname;
    var pos = a.indexOf(b);
    var path = a.substring(0, pos);
    a = a.substring(a.indexOf("/") + 2, a.length);
    a = a.substring(a.indexOf("/") + 1, a.length);
    var pathName = a.substring(0, a.indexOf("/"));
    return path + "/" + pathName + "/" + request;
}

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