PHP Binary to Hex with leading zeros

Question

I have the follow code:

Which works fine, and I get a valu

Answer 1

You can do it very easily with sprintf:

// Get $hex as 3 hex digits with leading zeros if required. 
$hex = sprintf('%03x', bindec($binary));

// Get $hex as 4 hex digits with leading zeros if required. 
$hex = sprintf('%04x', bindec($binary));

To handle a variable number of bits in $binary:

  $fmt = '%0' . ((strlen($binary) + 3) >> 2) . 'x';
  $hex = sprintf($fmt, bindec($binary));