<?php
/*
* Adds "value1" to "value2" and stores the result into "result".
* opcode number: 1
*/
echo 1 + 2;
?>
Function name: (null)
Compiled variables: none
| line | # | op | fetch | ext | return | operands |
|---|---|---|---|---|---|---|
| 6 | 0 | ADD | ~0 | 1,2 | ||
| 1 | ECHO | ~0 | ||||
| 7 | 2 | RETURN | 1 |
For you information
Using +0 for casting a string into a integer works but it generates a warning in php 7.1+
PHP 5.X: "abc"+0 = 0
PHP 7.0: "abc"+0 = 0
PHP 7.1: "abc"+0 = 0 (Warning: A non-numeric value encountered in..)
The correct way (if you are using it for casting) is to do
PHP 7.1: (int)"abc" = 0
$ php -v
PHP 7.1.5 (cli) (built: May 13 2017 13:30:32) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies
with Zend OPcache v7.1.5, Copyright (c) 1999-2017, by Zend Technologies
with Xdebug v2.5.4, Copyright (c) 2002-2017, by Derick Rethans
--------------------------------
$ cat test.php
<?php
echo 1 + 2;
--------------------------------
$ php -dvld.active=1 test.php
Finding entry points
Branch analysis from position: 0
Jump found. (Code = 62) Position 1 = -2
filename: /data/test.php
function name: (null)
number of ops: 3
compiled vars: none
line #* E I O op fetch ext return operands
-------------------------------------------------------------------------------------
2 0 E > EXT_STMT
1 ECHO 3
4 2 > RETURN 1
<?php
echo 1+2;
?>
qiufeng@ubuntu:~$ php -dvld.active=1 test.php
Finding entry points
Branch analysis from position: 0
Return found
filename: /home/qiufeng/test.php
function name: (null)
number of ops: 3
compiled vars: none
line # * op fetch ext return operands
---------------------------------------------------------------------------------
2 0 > ADD ~0 1, 2
1 ECHO ~0
3 2 > RETURN 1
branch: # 0; line: 2- 3; sop: 0; eop: 2
path #1: 0,