如何使用preg_match验证hh：mm中的时间字符串？

Question

Below are the following possiblities. Time is for 12 hours

 Inputs          Output should as

"05:30"           True
"asasds"          FALSE
"05:30:sads"      FALSE
"ADAS:05:40"      FALSE
"04:30:40"        FALSE

Below is the code that I wrote,

 $value = "05:30" ;
if(!preg_match("/(1[012]|0[0-9]):([0-5][0-9])/", $value)){
    echo "failed"; exit;
}
echo "passed"; exit;

But it prints as passed if I give the $value = "05:30:asdsa". However I need the output to be "failed".

Answer 1

Use anchors to match the start and the end, e.g.

!preg_match("/^(1[012]|0[0-9]):([0-5][0-9])$/", $value)
            //^ See here                   ^