javascript 常见工具函数（六）

51.格式化数字：

 /**
     * 格式化数字
     * @param {number} num
     */
    static formatNumber$(num) {
        if (isNaN(num)) return "0";
        if (num > 1000000) {
            num /= 1000000;
            if (num >= 100) {
                return Math.round(num) + "m"
            } else if (num >= 10) {
                num = num.toFixed(1);
                return num + "m"
            } else {
                num = num.toFixed(2);
                return num + "m"
            }
        } else if (num > 1000) {
            num /= 1000;
            if (num >= 100) {
                return Math.round(num) + "k"
            } else if (num >= 10) {
                num = num.toFixed(1);
                return num + "k"
            } else {
                num = num.toFixed(2);
                return num + "k"
            }
        } else {
            return Math.round(num);
        }
    }

52.钱的单位转化：

  // 钱单位
    static cMoney$(value) {
        let absVal = Math.abs(Math.floor(value));
        let sVal = absVal.toLocaleString().replace(/[,]/g, '');


        let cnt = Math.floor((sVal.length - 1) / 3);
        let unit = Utils$.moneyUnit[cnt];


        let subStr = sVal.substring(0, sVal.length - (cnt > 0 ? cnt * 3 - 1 : 0));
        let val = (value < 0 ? -1 : 1) * Number(subStr);
        return cnt > 0 ? val / 10 + unit : val;
    }

Utils$.moneyUnit = ["", "K", "M", "B", "T", "aa", "bb", "cc", "dd", "ee",
    "ff", "gg", "hh", "ii", "jj", "kk", "ll", "mm", "nn", "oo",
    "pp", "qq", "rr", "ss", "tt", "uu", "vv", "ww", "xx", "yy",
    "zz", "AA", "BB", "CC", "DD", "EE", "FF", "GG", "HH", "II",
    "JJ", "KK", "LL", "MM", "NN", "OO", "PP", "QQ", "RR", "SS",
    "TT", "UU", "VV", "WW", "XX", "YY", "ZZ",]

53.日期转化：

Date.prototype.format = function (fmt) {
    var o = {
        "M+": this.getMonth() + 1, //月份
        "d+": this.getDate(), //日
        "h+": this.getHours(), //小时
        "m+": this.getMinutes(), //分
        "s+": this.getSeconds(), //秒
        "q+": Math.floor((this.getMonth() + 3) / 3), //季度
        "S": this.getMilliseconds() //毫秒
    };


    if (/(y+)/.test(fmt))
        fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));
   
    for (var k in o){
        if (new RegExp("(" + k + ")").test(fmt)) {
            fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));
        }
    }
   
    return fmt;
};

54.执行回调：

/**
* 回调函数（允许带参）
* @param {Function} cb 待回调的函数
* @param args 参数
* @returns {any} 回调函数执行后的返回值
*/
function doCallback$1 ( cb ) {
    // body...
    if (typeof cb === "function") {
        let args = Array.prototype.slice.call(arguments);
        args.shift();
       
        // cb
        return cb.apply(null, args)
    }


    return null
}

55.生成指定位数的随机字符串：

/**
* 生成从min到max之间的随机数，其中min和max都必须大于0的整数
* 若为一个参数，则生成1到min之间的随机数
* 若为两个参数，则生成min到max之间的随机数
* 其他参数个数，返回错误0
* @param {number} min 最小随机数
* @param {number} max 最大随机数
* @returns {number}
*/
function random (min, max) {
    // body...
    if (min < 0 || max <= 0) {
        return 0;
    }


    switch(arguments.length) {
        case 1:
            return Math.floor(Math.random() * min + 1);
        case 2:
            return Math.floor(Math.random() * (max - min + 1) + min);
        default:
            return 0;
    }
}


/**
* 生成指定位数的随机字符串
* @param {number} count 需要生成的字符数量
* @returns {string}
*/
function generateString ( count ) {
    // body...
    let str = '';


    if (typeof count === "number") {
        for (let i = 0; i < count; i++) {
            if (Math.random() < 0.5) {
                str += String.fromCharCode(random('0'.charCodeAt(), '0'.charCodeAt() + 9));
            }
            else {
                str += String.fromCharCode(random('a'.charCodeAt(), 'a'.charCodeAt() + 25));
            }
        }
    }


    return str
}

56.超过长度的字符串截取指定长度，超出部分...显示：

/**
* 超过长度的字符截取指定长度，超出部分以...显示
* @param {string} str 需要裁剪的字符
* @param {number} len 最大字符长度
* @returns {string}
*/
function cutString (str, len) {
    var newLength = 0;
    var newStr = "";
    var chineseRegex = /[^\x00-\xff]/g;
    var singleChar = "";
    var strLength = str.replace(chineseRegex, "**").length;
    if (strLength > len) {
        for (var i = 0; i < strLength; i++) {
            singleChar = str.charAt(i).toString();
            if (singleChar.match(chineseRegex) != null) {
                newLength += 2;
            }
            else {
                newLength++;
            }
            if (newLength > len) {
                break;
            }


            newStr += singleChar;
        }


        if (strLength > len) {
            newStr += "...";
        }
    } else {
        newStr = str;
    }
   
    return newStr;
}

57.打乱数组：

/**
* 打乱数组（影响原数组对象）
* @param {Array} arr
*/
function shuffleArray (arr) {
    if (Array.isArray(arr)) {
        for (let i = 0; i < arr.length; i++) {
            let randomIndex = Math.round(Math.random() * (arr.length - 1 - i)) + i;
            let temp = arr[randomIndex];
            arr[randomIndex] = arr[i];
            arr[i] = temp;
        }
    }
}

58.数字按照粒度拆分，个十百千万：

 static checkNum(num: string, size: number) {
    let count = parseInt(num).toString();
    let len = count.length;
    if (len <= size) return num;
    let r = len % size;
    let regExp = new RegExp('\\d{' + size + '}', 'g')
    return r > 0 ? count.slice(0, r) + ',' + count.slice(r, len).match(regExp).join(',') : count.match(regExp).join(',')
  }

59.定时刷新网页：

var timeout = prompt("设置刷新时间间隔[S]");  
    var current = location.href;  
    if(timeout > 0)  
    {  
        setTimeout('reload()', 1000 * timeout);  
    }  
    else  
    {  
        location.replace(current);  
    }  


    function reload()  
    {  
        setTimeout('reload()', 1000 * timeout);  
        var fr4me = '<frameset cols=\'*\'>\n<frame src=\'' + current + '\' />';  
        fr4me += '</frameset>';  


        with(document)  
        {  
            write(fr4me);  
            void(close());  
        };  
    }

60读取地址栏中的参数：

 /*
        当前网址获取url 中的参数
        paramName:参数名
     */
    static getUrlParam(paramName: string): string {
   
        let url = location.href; //取得整个地址栏
        let indexQuestion = url.indexOf("?");
        let paramInUrl = '';
       
        paramInUrl = url.substr(indexQuestion + 1); //取得所有参数
        let arrParam = paramInUrl.split("&"); //各个参数放到数组里
        for (let i = 0; i < arrParam.length; i++) {
            let indexEqual = arrParam[i].indexOf("=");
            if (indexEqual > 0) {
                let name = arrParam[i].substring(0, indexEqual);
                let value = arrParam[i].substr(indexEqual + 1);
                if(name==paramName) return value;
            }
        }
     
        console.log('没有在url中找到 参数' + paramName);
        return ;
    }