preg_match ('/ ^ \ d * $ /', $ nr_procedure)? 'f': 't'; - what are you doing ? php

The function preg_match makes a match of a regular expression in a string, returning 1 if match, 0 if it did not match% and false if an error has occurred.

You pass two parameters to it, the first being a regular expression and the second the string to veriricada.

In your case the regex is /^\d*$/ , defining each part:

  

/ indicates the beginning of the regular expression

     

^ indicates that your pattern starts as follows

     

\ d defines numeric values

     

* sets the previous element can occur 0 or No times

     

$ indicates that your string should end here

     

/ indicates the end of the regular expression

You can see more about preg_match href="http://php.net/manual/pt_BR/function.preg-match.php"> here.

In your example you have a complete ternary .

preg_match('/^\d*$/', $nr_procedimento) ? 'f' : 't';

In this case, if the content of the $nr_procedimento der match the regex shown, the f will be returned by the ternary otherwise% is returned t .

It's a regular expression to fetch a line that starts and ends with numbers. The heaped symbols are known as meta characters , each one has a function:

^ - means start line.

\d - is an abbreviation for [0-9] or just numbers.

* - makes the combination greedy, if as many times as possible the defined pattern.

$ - means end of line