Js仿php日期格式化方式

/**

• 仿php日期格式化方式
• @description Exp: date(‘Y-m-d H:i:s’, ‘1514736000’);
• @param {格式化字符串} format
• @param {时间戳} timestamp
  */

/**
* 仿php日期格式化方式
* @description Exp: date('Y-m-d H:i:s', '1514736000');
* @param {格式化字符串} format
* @param {时间戳} timestamp
*/
var fromatDate = function (format, timestamp) {
   // let jsdate = ((timestamp) ? new Date(timestamp * 1000) : new Date());
   let jsdate = ((timestamp) ? new Date(timestamp) : new Date());
   let pad = function (n, c) {
       if ((n = n + '').length < c) {
           return new Array(++c - n.length).join('0') + n;
       } else {
           return n;
       }
   };
   let txtWeekdays = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
   let txtOrdin = { 1: 'st', 2: 'nd', 3: 'rd', 21: 'st', 22: 'nd', 23: 'rd', 31: 'st' };
   let txtMonths = ['', 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'];
   let f = {
       // Day
       d: function () { return pad(f.j(), 2); },
       D: function () { return f.l().substr(0, 3); },
       j: function () { return jsdate.getDate(); },
       l: function () { return txtWeekdays[f.w()]; },
       N: function () { return f.w() + 1; },
       S: function () { return txtOrdin[f.j()] ? txtOrdin[f.j()] : 'th'; },
       w: function () { return jsdate.getDay(); },
       z: function () { return (jsdate - new Date(jsdate.getFullYear() + '/1/1')) / 864e5 >> 0; },

       // Week
       W: function () {
           let a = f.z();
           let b = 364 + f.L() - a;
           let nd2;
           let nd = (new Date(jsdate.getFullYear() + '/1/1').getDay() || 7) - 1;
           if (b <= 2 && ((jsdate.getDay() || 7) - 1) <= 2 - b) {
               return 1;
           } else {
               if (a <= 2 && nd >= 4 && a >= (6 - nd)) {
                   nd2 = new Date(jsdate.getFullYear() - 1 + '/12/31');
                   return fromatDate('W', Math.round(nd2.getTime() / 1000));
               } else {
                   return (1 + (nd <= 3 ? ((a + nd) / 7) : (a - (7 - nd)) / 7) >> 0);
               }
           }
       },

       // Month
       F: function () { return txtMonths[f.n()]; },
       m: function () { return pad(f.n(), 2); },
       M: function () { return f.F().substr(0, 3); },
       n: function () { return jsdate.getMonth() + 1; },
       t: function () {
           let n;
           if ((n = jsdate.getMonth() + 1) === 2) {
               return 28 + f.L();
           } else {
               if ((n & 1 && n < 8) || (!(n & 1) && n > 7)) {
                   return 31;
               } else {
                   return 30;
               }
           }
       },

       // Year
       L: function () { let y = f.Y(); return (!(y & 3) && (y % 1e2 || !(y % 4e2))) ? 1 : 0; },
       Y: function () { return jsdate.getFullYear(); },
       y: function () { return (jsdate.getFullYear() + '').slice(2); },

       // Time
       a: function () { return jsdate.getHours() > 11 ? 'pm' : 'am'; },
       A: function () { return f.a().toUpperCase(); },
       B: function () {
           // peter paul koch:
           let off = (jsdate.getTimezoneOffset() + 60) * 60;
           let theSeconds = (jsdate.getHours() * 3600) + (jsdate.getMinutes() * 60) + jsdate.getSeconds() + off;
           let beat = Math.floor(theSeconds / 86.4);
           if (beat > 1000) beat -= 1000;
           if (beat < 0) beat += 1000;
           if ((String(beat)).length === 1) beat = '00' + beat;
           if ((String(beat)).length === 2) beat = '0' + beat;
           return beat;
       },
       g: function () { return jsdate.getHours() % 12 || 12; },
       G: function () { return jsdate.getHours(); },
       h: function () { return pad(f.g(), 2); },
       H: function () { return pad(jsdate.getHours(), 2); },
       i: function () { return pad(jsdate.getMinutes(), 2); },
       s: function () { return pad(jsdate.getSeconds(), 2); },
       // Timezone
       O: function () {
           let t = pad(Math.abs(jsdate.getTimezoneOffset() / 60 * 100), 4);
           if (jsdate.getTimezoneOffset() > 0) t = '-' + t; else t = '+' + t;
           return t;
       },
       P: function () { let O = f.O(); return (O.substr(0, 3) + ':' + O.substr(3, 2)); },
       // Full Date/Time
       c: function () { return f.Y() + '-' + f.m() + '-' + f.d() + 'T' + f.h() + ':' + f.i() + ':' + f.s() + f.P(); },
       U: function () { return Math.round(jsdate.getTime() / 1000); }
   };

   return format.replace(/[\\]?([a-zA-Z])/g, function (t, s) {
       let ret = '';
       if (t !== s) {
           ret = s;
       } else if (f[s]) {
           ret = f[s]();
       } else { ret = s; }
       return ret;
   });
};

export default fromatDate;