Checks value IF is a valid date

is_date.php

function is_date($date){
    // date example mm-dd-year -> 09-25-2012
    $datechunks = explode("-",$date);
    if(sizeof($datechunks)==3){
        if(is_numeric($datechunks[0]) && is_numeric($datechunks[1]) && is_numeric($datechunks[2]))
        {
            // now check if its a valid date
            if(checkdate($datechunks[0], $datechunks[1], $datechunks[2])){
            return true;
            }else{
            return false;
            }

        }else{
        return false;
        }
    }

}

Nice, never knew about the checkdate() function in PHP.
For the sake of minimalising the amount of return statements, this should also work:

public static function is_date($date){
// date example mm-dd-year -> 09-25-2012
$datechunks = explode("-",$date);
if((sizeof($datechunks)==3) && (is_numeric($datechunks[0]) && is_numeric($datechunks[1]) && is_numeric($datechunks[2])))
if(checkdate($datechunks[0], $datechunks[1], $datechunks[2]))
return true;
return false;
}

Pardon the lack of styling - should probably read up on how to get GitHub to keep the code formatting.

public static function is_date($date){
// date example mm-dd-year -> 09-25-2012
$datechunks = explode("-",$date);
if((sizeof($datechunks)==3) && (is_numeric($datechunks[0]) && is_numeric($datechunks[1]) && is_numeric($datechunks[2])))
    if(checkdate($datechunks[0], $datechunks[1], $datechunks[2]))
        return true;
return false;
}

There we go.

Thank you Chris :-) I also didn't knew about it, its applied only in > PHP 5.3 version

Some brackets are missing but I got your point.

Ah, okay. Maybe I'm a bit rusty on my PHP :P. Great feature though, makes live easier.

The brackets are optional if you're only running one statement after an if statement.

Example:

if($a == 1)
    echo "true";

is equivalent to

if($a == 1){
    echo "true";
}

However, the following would require brackets:

if($a == 1)
     echo "true";
     echo "something else";

The above example would always echo "something else", but only echo "true" if $a == 1. If statements without brackets only run the first statement after them.

If you want to see the difference, try this code out:

<?php
$a = 1;

if($a == 1)
    echo "A is 1";
    echo "This is not part of the bracket-less if statement.";

if($a == 1){
    echo "A is 1";
    echo "This is part of the if statement as brackets will allow for more than one statement to be executed";
}
?>

Run the above and try switching $a from 1 to 0, and you'll get the idea :). Sometimes it may be neater not to use brackets, but it's really just a personal preference. It's also easier to make a mistake when not using brackets.

I haven't tried this, but you might be able to simplify a little further.

public static function is_date($date){
    // date example mm-dd-year -> 09-25-2012
    $datechunks = explode("-",$date);
    if((sizeof($datechunks)==3)
        return checkdate($datechunks[0], $datechunks[1], $datechunks[2]);

    return false;
}

The above will first explode the input, and if the number of items in the array is 3, then it will check to see if it's a date - otherwise return false. If there are 3 items in the array, then it will return the value of checkdate() which should either return true or false. I think checkdate() takes integers for input, so you may not require the is_numeric() checks. I could be wrong, though.

The above code is the same as this, if you prefer brackets:

public static function is_date($date){
    // date example mm-dd-year -> 09-25-2012
    $datechunks = explode("-",$date);
    if((sizeof($datechunks)==3){
        return checkdate($datechunks[0], $datechunks[1], $datechunks[2]);
    }

    return false;
}

Anyway, I just thought I'd share :).

I already tried that and you get an error in case any value isn't numeric. So you have to check each (day/month/year) if its a valid number and the go for checkdate function.

As for the brackets, I was troubled about the sequence return true; return false; you had in your code. Anyway later tonight I'll refactor it and test it and try to shorten it as much as I can :-)

Ah k, fair enough :).

The return statement automatically exits the function once reached. My reordering of the return statements simply saves if/else lines.

For example:

if ($x == 1) {
    return false;
} else {
    return true;
}

Is the same as:

if ($x != 1)
    return true;
return false;

Because the first return statement has been reached, there's no need to go any further in the function, so PHP will ignore everything below "return true;" (should $x not equal 1, that is.) Otherwise, if $x is 1, it will return false because the "return true;" statement is skipped.