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<?php // inspired by discussion at: http://stackoverflow.com/questions/11158772/assigning-null-to-a-variable-in-php-what-does-that-do $a = 1; $a = null; echo isset($a) ? 'true' : 'false', "\n"; // false var_dump($a); // 'NULL' -- but no error notice - bug ? type changed to NULL unset($a); // now variable undefined var_dump($a); // error notice and value NULL echo isset($a) ? 'true' : 'false', "\n"; // false
Finding entry points
Branch analysis from position: 0
2 jumps found. (Code = 43) Position 1 = 4, Position 2 = 6
Branch analysis from position: 4
1 jumps found. (Code = 42) Position 1 = 7
Branch analysis from position: 7
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: 6
2 jumps found. (Code = 43) Position 1 = 18, Position 2 = 20
Branch analysis from position: 18
Branch analysis from position: 20
filename:       /in/rHa1N
function name:  (null)
number of ops:  24
compiled vars:  !0 = $a
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    3     0  E >   ASSIGN                                                   !0, 1
    4     1        ASSIGN                                                   !0, null
    5     2        ISSET_ISEMPTY_CV                                         !0
          3      > JMPZ                                                     ~3, ->6
          4    >   QM_ASSIGN                                        ~4      'true'
          5      > JMP                                                      ->7
          6    >   QM_ASSIGN                                        ~4      'false'
          7    >   ECHO                                                     ~4
          8        ECHO                                                     '%0A'
    6     9        INIT_FCALL                                               'var_dump'
         10        SEND_VAR                                                 !0
         11        DO_ICALL                                                 
    7    12        UNSET_CV                                                 !0
    8    13        INIT_FCALL                                               'var_dump'
         14        SEND_VAR                                                 !0
         15        DO_ICALL                                                 
    9    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


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