Copied from duplicate bug:

From manual page: http://www.php.net/internals2.opcodes.jmpznz
---

Explanation of this opcode is missing. Correct explanation should be:
Jump to the address of op2 if value is zero, or to address given in extended_data 
if value is not zero.

Also, the example code for 
http://www.php.net/manual/en/internals2.opcodes.declare-function.php is wrong. 
Should be something like:

if($test) {
  function a() { }
}

i.e. declaring functions depending on conditions, top-level functions are 
registered immediately without any bytecode

This bug has been fixed in the documentation's XML sources. Since the
online and downloadable versions of the documentation need some time
to get updated, we would like to ask you to be a bit patient.

Thank you for the report, and for helping us make our documentation better.