如何使用子字符串检查$ _POST

i just want to check whether my $_POST has 'Project :' in it or not. But its getting failed ! Can i know why ?

if (substr($_POST['project'],0,8) == 'Project :'){ $project = $_POST['project']; }

You can try the following

if(strpos($_POST['project'], 'Project :') !== false) {

   $project = $_POST['project'];
}

I suggest reading the documentation on the substr function. The second parameter is the starting position, the third is the length. That means you can only have an 8 character output.

Project :
        ^
123456789

You got one character too many. Try changing the 0,8 to 0,9

Using the link I provided you in a comment.

If the use of substr isn't mandatory, I suggest you to use strpos that way:

if (strpos($_POST['project'], 'Project :') !== false) {
    $project = $_POST['project'];;
}

Hope it helps.