Sort out some JavaScript time processing extended functions

In JavaScript, time processing is often used. Recently, I want to build my own code library, sort out several js processing time functions that I used earlier, and share them with you. The code library will be added and modified in the future.

Converts a string to a date object.

Sometimes the string needs to be converted to a Date object, but the new Date ("") is not supported in IE to instantiate a Date object, which is supported in ff, so an extension function is written, converts a string such as yyyy-mm-dd Or dd/mm/yyyy to a date object. The Code is as follows:

/* Function: convert a string to a string in the format of yyyy-mm-dd Or dd/mm/yyyy. Return the Date object. Note: in IE, Date objects cannot be directly instantiated, such as new Date ("") */Date. prototype. convertDate = function (date) {var flag = true; var dateArray = date. split ("-"); if (dateArray. length! = 3) {dateArray = date. split ("/"); if (dateArray. length! = 3) {return null;} flag = false;} var newDate = new Date (); if (flag) {// month starts from 0 newDate. setFullYear (dateArray [0], dateArray [1]-1, dateArray [2]);} else {newDate. setFullYear (dateArray [2], dateArray [1]-1, dateArray [0]);} newDate. setHours (0, 0, 0); return newDate ;};

Test:

<script type="text/javascript">　　document.writeln(new Date().convertDate("7/12/2011"));</script>

Output: Wed Dec 07 2011 17:30:58 GMT + 0800

Calculate the difference between two dates

This function can calculate the difference between two dates (millisecond/Second/minute/hour/day), mainly using the getTime () function and Math. floor () function, the Code is as follows:

/* Function: calculate the difference parameter between two dates: date is the date object flag: ms-millisecond, s-second, m-minute, h-hour, d-Day, m-month, y-year return: the difference between the current date and Date in milliseconds/Second/minute/hour/day */date. prototype. dateDiff = function (date, flag) {var msCount; var diff = this. getTime ()-date. getTime (); switch (flag) {case "ms": msCount = 1; break; case "s": msCount = 1000; break; case "m ": msCount = 60*1000; break; case "h": msCount = 60*60*1000; break; case "d": msCount = 24*60*60*1000; break;} return Math. floor (diff/msCount );};

Test:

<script type="text/javascript">　　var d1 = new Date().convertDate("2011-04-08");　　var d2 = new Date().convertDate("2011-04-07");　　document.writeln(d1.dateDiff(d2, 'd'));</script>

Determines whether a year is a leap year.

/* Function: determines whether a year is a leap year. Return Value: whether it is a leap year */Date. prototype. isLeapYear = function () {var year = this. getFullYear (); return (year % 4 = 0) & (year % 100! = 0 | year % 400 = 0 );}

Test:

<Script type = "text/javascript"> document. writeln (new Date (). convertDate ("2000-04-08"). isLeapYear () +"
"); Document. writeln (new Date (). convertDate (" 2011-04-08 "). isLeapYear () +"
"); </Script> // result: // true // false

Format date

This function was searched from the Internet and slightly modified. It is similar to the Format function in. net, and the formatted string such as "yyyy-MM-dd" is passed in. net. The formatted date is returned.

/* Function: format the date parameter: formatStr-Format String d: displays the day as a number without leading zero, for example, 1dd: displays the day as a number with leading zero, for example, 01ddd: display the day as an abbreviation, for example, Sundddd: display the day as the full name, for example, SundayM: displays the month as a number without leading zero, for example, 1 MM: display the month as a number with leading zeros, for example, 01MMM: display the month as an abbreviation, for example, JanMMMM: display the month as the full month name, such as Januaryyy: yyyy: yyyy: use the 12-hour system to display the hour as a digit with a leading zero. Use the 24-hour system to display the hour as a digit without a leading zero. HH: use the 24-hour system to display the hour as a number m with a leading zero: display the minute as a number mm without a leading zero: display the minute as a number s with a leading zero: display second as a number without leading zero ss: Display second as a number with leading zero l: Display millisecond as a number without leading zero l L: display the data in milliseconds as a number with leading zeros. tt: Show am/pmTT: Show AM/PM. Return: formatted Date */Date. prototype. format = function (formatStr) {var date = this;/* function: Fill 0 character parameter: value-string to be filled, length-total length returned: filled string */var zeroize = function (value, length) {if (! Length) {length = 2;} value = new String (value); for (var I = 0, zeros = ''; I <(length-value. length); I ++) {zeros + = '0';} return zeros + value;}; return formatStr. replace (/"[^"] * "| '[^'] * '| \ B (?: D {1, 4} | M {1, 4} | yy (?: Yy )? | ([HHmstT]) \ 1? | [LLZ]) \ B/g, function ($0) {switch ($0) {case 'D': return date. getDate (); case 'dd': return zeroize (date. getDate (); case 'ddd ': return ['sun', 'mon', 'tue ', 'wed', 'thr', 'fri ', 'sat '] [date. getDay ()]; case 'ddddd': return ['sunday', 'monday', 'tuesday', 'wednesday', 'thursday', 'Friday ', 'saturday'] [date. getDay ()]; case 'M': return date. getMonth () + 1; case 'mm': return zeroize (date. getMonth () + 1); case 'Mmm': return ['Jan ', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug ', 'sept', 'oct', 'nov', 'dec '] [date. getMonth ()]; case 'mmmm': return ['january ', 'february', 'march', 'marril', 'may', 'june', 'july ', 'August ', 'September', 'October ', 'November', 'december '] [date. getMonth ()]; case 'yy': return new String (date. getFullYear ()). substr (2); case 'yyyy': return date. getFullYear (); case 'H': return date. getH Ours () % 12 | 12; case 'hh': return zeroize (date. getHours () % 12 | 12); case 'H': return date. getHours (); case 'hh': return zeroize (date. getHours (); case 'M': return date. getMinutes (); case 'mm': return zeroize (date. getMinutes (); case's ': return date. getSeconds (); case 'ss': return zeroize (date. getSeconds (); case 'l': return date. getMilliseconds (); case'll ': return zeroize (date. getMilliseconds (); ca Se 'TT': return date. getHours () <12? 'Am': 'pm'; case 'TT': return date. getHours () <12? 'Am': 'pm ';}});}

Test:

<Script type = "text/javascript"> document. writeln (new Date (). format ("yyyy-MM-dd hh: mm: ss"); </script> // result: // 10:13:37

In the future work and study, your code library will be constantly added and improved. Please advise if you have any questions.