js-core

LockMap.js

export class LockMap extends Map {
  constructor (args) {
    const map = new Map(args)
    map.set = () => {
      console.error('禁止修改枚举常量')
    }
    map.delete = () => {
      console.error('禁止修改枚举常量')
    }
    map.clear = () => {
      console.error('禁止修改枚举常量')
    }
    return map
  }
}

showDate.js

/**
 * 获取当前时间
 * @return string
 * @param ("Y-M-D h:m:s") 或 ("Y-M-D h:m:s",时间戳)
 * YMDhms直接替换对应时间单位，格式可自由替换
 * 没有参数直接返回Y-M-D h:m:s(如2018-01-01 12:21:45)
 * 有参数则直接替换
 */
function showDate(format, time) {
    let now;
    const add0 = (m) => (m < 10 ? "0" + m : m + "");
    const applyNew = (ctor, args) => {
        let applyArgs = [{}].concat(args || []);
        let f = Function.prototype.bind.apply(ctor, applyArgs);
        return new f();
    };
    if (
        arguments.length == 2 &&
        time &&
        String(new Date(time)) === "Invalid Date"
    ) {
        let arr = time.match(/\d+/g);
        now = applyNew(Date, arr);
    } else if (arguments.length != 2) {
        now = new Date();
    } else {
        now = new Date(time);
    }
    let year = now.getFullYear();
    let month = add0(now.getMonth() + 1);
    let date = add0(now.getDate());
    let hour = add0(now.getHours());
    let minute = add0(now.getMinutes());
    let seconds = add0(now.getSeconds());
    if (!arguments.length) {
        return (
            year +
            "-" +
            month +
            "-" +
            date +
            " " +
            hour +
            ":" +
            minute +
            ":" +
            seconds
        );
    } else if (arguments.length > 0) {
        if (format.indexOf("Y") > -1) {
            format = format.replace(/Y/g, year);
        }
        if (format.indexOf("M") > -1) {
            format = format.replace(/M/g, month);
        }
        if (format.indexOf("D") > -1) {
            format = format.replace(/D/g, date);
        }
        if (format.indexOf("h") > -1) {
            format = format.replace(/h/g, hour);
        }
        if (format.indexOf("m") > -1) {
            format = format.replace(/m/g, minute);
        }
        if (format.indexOf("s") > -1) {
            format = format.replace(/s/g, seconds);
        }
        return format;
    }
}
console.log(showDate("Y-M-D h:m:s"))

utf8转utf16.js

/**
* 将编码由utf8转为utf16
* @param {需要编码的字符串} str 
*/
function  utf8to16(str) {
    let out, i, len, c;
    let char2, char3;
    out = "";
    len = str.length;
    i = 0;
    while (i < len) {
        c = str.charCodeAt(i++);
        switch (c >> 4) {
            case 0:
            case 1:
            case 2:
            case 3:
            case 4:
            case 5:
            case 6:
            case 7:
                // 0xxxxxxx
                out += str.charAt(i - 1);
                break;
            case 12:
            case 13:
                // 110x xxxx   10xx xxxx
                char2 = str.charCodeAt(i++);
                out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
                break;
            case 14:
                // 1110 xxxx  10xx xxxx  10xx xxxx
                char2 = str.charCodeAt(i++);
                char3 = str.charCodeAt(i++);
                out += String.fromCharCode(((c & 0x0F) << 12) |
                    ((char2 & 0x3F) << 6) |
                    ((char3 & 0x3F) << 0));
                break;
        }
    }
    return out;
}

乘法字符串.js

/**
 * @param {string} num1
 * @param {string} num2
 * @return {string}
 */
var multiply = function(num1, num2) {
  if(num1==0 || num2==0) return "0"
  const res=[];// 结果集
  for(let i=0;i<num1.length;i++){
      let tmp1=num1[num1.length-1-i]; // num1尾元素
      for(let j=0;j<num2.length;j++){
          let tmp2 = num2[num2.length-1-j]; // num2尾元素
          let pos = res[i+j] ? res[i+j]+tmp1*tmp2 : tmp1*tmp2;// 目标值 ==》三元表达式，判断结果集索引位置是否有值
          res[i+j]=pos%10; // 赋值给当前索引位置
          // 目标值是否大于10 ==》是否进位 这样简化res去除不必要的"0"
          pos >=10 && (res[i+j+1]=res[i+j+1] ? res[i+j+1]+Math.floor(pos/10) : Math.floor(pos/10));
      }
  }
  return res.reverse().join("");
};

分转两位小数.js

/**
* 数值转换为两位数的金额
* @param {*} rmb 为整数
*/
function showMoney(a) {
    a = String(a);
    const l = a.length;
    if (l > 2) {
        return a.replace(/(\d{2})$/g, "\.$1")
    } else if (l == 2) {
        return "0." + a;
    } else if (l == 1) {
        return "0.0" + a;
    }
}

千位符.js

/**
* 单位为元的金额的千位符显示
* @param {*} rmb 为整数
*/
function showThousandMoney(rmb) {
    return parseFloat(rmb).toFixed(2).replace(/(\d{1,3})(?=(\d{3})+(?:\.))/g, "$1,")
}

整数千位符.js

/**
* 整数的千位符显示
* @param {*} num 为整数
*/
export function showThousandNum (num) {
  return String(num).replace(/\d{1,3}(?=(\d{3})+$)/g, '$&,')
}

给url添加参数.js

// 给url添加参数
function   urlAddParams(url, params) {
    if (typeof (url) == 'undefined' || url == null || url == '') {
        return '';
    }
    if (typeof (params) == 'undefined' || params == null || typeof (params) != 'object') {
        return url;
    }
    url += (url.indexOf("?") != -1) ? "" : "?";
    for (const k in params) {
        url += ((url.indexOf("=") != -1) ? "&" : "") + k + "=" + encodeURI(params[k]);
    }
    return url;
}

节流防抖.js

// 节流
function throttle(func, wait){
    var timer
    return function(){
        if(!timer){
            func.apply(this,arguments)
            timer = setTimeout(()=>{
                timer = null
            },wait)
        }
    }
}

// 防抖
function debounce(func,wait){
    var timer
    return function(){
        if(timer) clearTimeout(timer)
        var isRun = !timer
        setTimeout(()=>{
            timer = null
        },wait)
        if(isRun){
            func.apply(this,arguments)
        }
    }
}

获取距离今天的N天的日期.js

/**  
* 获取距离今天的N天的日期  N可正可负 
* @param {Number} interval default 0  -n 表示前几天  n表示后几天 
*/
function getIntervalDate(interval = 0)s{
    interval = Number(interval)
    let currentDate = new Date();
    currentDate.setDate(currentDate.getDate() + interval);
    let year = currentDate.getFullYear();
    let month = (currentDate.getMonth() + 1) < 10 ? "0" + (currentDate.getMonth() + 1) : (currentDate.getMonth() + 1);
    let day = currentDate.getDate() < 10 ? "0" + currentDate.getDate() : currentDate.getDate();
    return year + "-" + month + "-" + day;
}

获取距离当前的时差.js

/**
* 获取距离当前的时差，天/时/分/秒
* @param {*} time 
*/
function  diffToNow(time) {
    let now = new Date().getTime();
    if (String(new Date(time)) == 'Invalid Date') {
        let arr = time.match(/\d+/g);
        time = applyNew(Date, arr);
    }
    time = new Date(time).getTime()
    let diffTime = Math.abs(time - now);
    let diffDays = parseInt(String(diffTime / 1000 / 3600 / 24))
    // 大于1天
    let diffYears = parseInt(String(diffDays / 365))
    if (diffYears > 1) {
        return `${String(diffYears)}年`
    }
    if (diffDays >= 1) {
        return `${String(diffDays)}天`
    }
    let diffHours = parseInt(String(diffTime / 1000 / 3600))
    // 大于1小时
    if (diffHours >= 1) {
        return `${String(diffHours)}小时`
    }
    let mins = parseInt(String(diffTime / 1000 / 60));
    let sec = parseInt(String(diffTime / 1000)) % 60;
    if (mins >= 1) {
        mins = mins % 60;
        return `${String(mins)}分`;
    } else {
        return `${String(sec)}秒`;
    }
}