php-regexHow to use regex in PHP to match datetime?

Regex (Regular Expressions) can be used in PHP to match datetime. The following example code block shows how to use regex to match a datetime string in the format of YYYY-MM-DD HH:MM:SS:

$datetime = '2020-01-01 12:00:00';
$pattern = '/^(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2})$/';

if (preg_match($pattern, $datetime, $matches)) {
    echo 'Matched!';
}

Output example

Matched!

Code explanation

• $datetime = '2020-01-01 12:00:00';: This is the datetime string to be matched.
• $pattern = '/^(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2})$/';: This is the regex pattern used to match the datetime string. It consists of 6 parts, each part is enclosed in parentheses and matches a number of digits. The first part matches 4 digits, the second part matches 2 digits, and so on.
• if (preg_match($pattern, $datetime, $matches)) {: This is the condition to check if the datetime string matches the regex pattern. The preg_match() function takes the regex pattern and the datetime string as parameters and returns true if the datetime string matches the regex pattern.
• echo 'Matched!';: This is the code to be executed if the datetime string matches the regex pattern.

Helpful links

• PHP preg_match() Function
• Regular Expressions Tutorial

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