1、使用 phpdbg_break_function()来给这个testFunc() 方法设置一个断点。当代码中调用这个函数的时候，就会进入这个断点中。

prompt> r
[Breakpoint #0 in testFunc() at /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php:11, hits: 1]
>00011: function testFunc(){
 00012:     global $i;
 00013:     $i += 3;
 
prompt> s
[L12         0x109eef620 EXT_STMT                                                                               /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
>00012:     global $i;
 00013:     $i += 3;
 00014:     echo "This is testFunc! i：" . $i, PHP_EOL;
 
prompt> s
[L12         0x109eef640 BIND_GLOBAL             $i                   "i"                                       /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
[L13         0x109eef660 EXT_STMT                                                                               /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
>00013:     $i += 3;
 00014:     echo "This is testFunc! i：" . $i, PHP_EOL;
 00015: }

2、直接进行了两次 s 单步，可以看到 global $i 对应的 opcode 操作是 BIND_GLOBAL 。继续向下操作。

prompt> s
[L13         0x109eef680 ASSIGN_ADD              $i                   3                                         /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
[L14         0x109eef6a0 EXT_STMT                                                                               /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
>00014:     echo "This is testFunc! i：" . $i, PHP_EOL;
 00015: }
 00016:
 
prompt> s
[L14         0x109eef6c0 CONCAT                  "This is testFunc!"+ $i                   ~1                   /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
[L14         0x109eef6e0 ECHO                    ~1                                                             /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
This is testFunc! i：4
[L14         0x109eef700 EXT_STMT                                                                               /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
[L14         0x109eef720 ECHO                    "n"                                                           /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
 
[L15         0x109eef740 EXT_STMT                                                                               /Users/zhangyue/MyDoc/博客文章/dev-blog/php/202006/source/PHPDebug互动扩展.php]
>00015: }
 00016:
 00017: testFunc();

以上就是php方法断点的实现，大家学会后也赶快尝试下实例操作吧。