3v4l.org

run code in 300+ PHP versions simultaneously
<?php preg_match('~a(?=\Kb)~', 'abc', $matches); print_r($matches); preg_match('~a(?=b\K)~', 'abc', $matches); print_r($matches);
Finding entry points
Branch analysis from position: 0
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/W9s8q
function name:  (null)
number of ops:  17
compiled vars:  !0 = $matches
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    3     0  E >   INIT_FCALL                                               'preg_match'
          1        SEND_VAL                                                 '%7Ea%28%3F%3D%5CKb%29%7E'
          2        SEND_VAL                                                 'abc'
          3        SEND_REF                                                 !0
          4        DO_ICALL                                                 
    4     5        INIT_FCALL                                               'print_r'
          6        SEND_VAR                                                 !0
          7        DO_ICALL                                                 
    6     8        INIT_FCALL                                               'preg_match'
          9        SEND_VAL                                                 '%7Ea%28%3F%3Db%5CK%29%7E'
         10        SEND_VAL                                                 'abc'
         11        SEND_REF                                                 !0
         12        DO_ICALL                                                 
    7    13        INIT_FCALL                                               'print_r'
         14        SEND_VAR                                                 !0
         15        DO_ICALL                                                 
         16      > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 8.0.0


preferences:
139.27 ms | 1000 KiB | 15 Q