在PHP中返回字符串中间的字符串

Question

using the function substr() how do I remove First and Last THREE letter in a string and return the ones remaining in the middle? eg:

$a = 'abc34828xyz';
$a = 'abc347283828xyz';
$a = 'abc347w83828xyz';
// return first 3
return $first = substr($a, 0, 3);
// return last 3
return $last = substr($a, -3);
// return the string in middle
// $mid = ? now how do we always get the ones in the middle

Answer 1

This should work for you:

(Just start with an offset of 3 and then take the length where you subtract 2*3 (6))

echo $middle = substr($a, 3, strlen($a)-6);