3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = 1; $a = null; var_dump($a); echo isset($a)? 'true' : 'false',"\n"; unset($a); var_dump($a); echo isset($a)? 'true' : 'false',"\n";
Finding entry points
Branch analysis from position: 0
2 jumps found. (Code = 43) Position 1 = 7, Position 2 = 9
Branch analysis from position: 7
1 jumps found. (Code = 42) Position 1 = 10
Branch analysis from position: 10
2 jumps found. (Code = 43) Position 1 = 18, Position 2 = 20
Branch analysis from position: 18
1 jumps found. (Code = 42) Position 1 = 21
Branch analysis from position: 21
1 jumps found. (Code = 62) Position 1 = -2
Branch analysis from position: 20
1 jumps found. (Code = 62) Position 1 = -2
Branch analysis from position: 9
2 jumps found. (Code = 43) Position 1 = 18, Position 2 = 20
Branch analysis from position: 18
Branch analysis from position: 20
filename:       /in/07kcK
function name:  (null)
number of ops:  24
compiled vars:  !0 = $a
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    2     0  E >   ASSIGN                                                   !0, 1
    3     1        ASSIGN                                                   !0, null
    4     2        INIT_FCALL                                               'var_dump'
          3        SEND_VAR                                                 !0
          4        DO_ICALL                                                 
    5     5        ISSET_ISEMPTY_CV                                         !0
          6      > JMPZ                                                     ~4, ->9
          7    >   QM_ASSIGN                                        ~5      'true'
          8      > JMP                                                      ->10
          9    >   QM_ASSIGN                                        ~5      'false'
         10    >   ECHO                                                     ~5
         11        ECHO                                                     '%0A'
    6    12        UNSET_CV                                                 !0
    7    13        INIT_FCALL                                               'var_dump'
         14        SEND_VAR                                                 !0
         15        DO_ICALL                                                 
    8    16        ISSET_ISEMPTY_CV                                         !0
         17      > JMPZ                                                     ~7, ->20
         18    >   QM_ASSIGN                                        ~8      'true'
         19      > JMP                                                      ->21
         20    >   QM_ASSIGN                                        ~8      'false'
         21    >   ECHO                                                     ~8
         22        ECHO                                                     '%0A'
         23      > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 8.0.0


preferences:
154.97 ms | 1395 KiB | 15 Q