change dd/mm/yy date format to yy/mm/dd using php

I'm having date 20/12/2001 in this formate . i need to convert i开发者_运维知识库n following format 2001/12/20 using php .

$var = explode('/',$date);
$var = array_reverse($var);
$final = implode('/',$var);

Your safest bet

<?php
$input = '20/12/2001';
list($day, $month, $year) = explode('/',$input);
$output= "$year/$month/$day";
echo $output."\n";

Add validation as needed/desired. You input date isn't a known valid date format, so strToTime won't work.

Alternately, you could use mktime to create a date once you had the day, month, and year, and then use date to format it.

If you're getting the date string from somewhere else (as opposed to generating it yourself) and need to reformat it:

$date = '20/12/2001';
preg_replace('!(\d+)/(\d+)/(\d+)!', '$3/$2/$1', $date);

If you need the date for other purposes and are running PHP >= 5.3.0:

$when = DateTime::createFromFormat('d/m/Y', $date);
$when->format('Y/m/d');
// $when can be used for all sorts of things

You will need to manually parse it.

1. Split/explode text on "/".
2. Check you have three elements.
3. Do other basic checks that you have day in [0], month in [1] and year in [2] (that mostly means checking they're numbers and int he correct range)
4. Put them together again.

$today = date("Y/m/d");

I believe that should work... Someone correct me if I am wrong.

You can use sscanf in order to parse and reorder the parts of the date:

$theDate = '20/12/2001';
$newDate = join(sscanf($theDate, '%3$2s/%2$2s/%1$4s'), '/');

assert($newDate == '2001/12/20');

Or, if you are using PHP 5.3, you can use the DateTime object to do the converting:

$theDate = '20/12/2001';
$date = DateTime::createFromFormat('d/m/Y', $theDate);
$newDate = $date->format('Y/m/d');

assert($newDate == '2001/12/20');

$date = Date::CreateFromFormat('20/12/2001', 'd/m/Y');
$newdate = $date->format('Y/m/d');