3v4l.org

run code in 300+ PHP versions simultaneously
<?php $nullvar[0]['a']['r']= null; if (isset($nullvar[0]['a']['r'])) { echo "set"; } else { echo "not set"; } if (is_null($nullvar[0]['a']['r'])) { echo "\nnull"; } else { echo "\nnot null"; }
Finding entry points
Branch analysis from position: 0
2 jumps found. (Code = 43) Position 1 = 8, Position 2 = 10
Branch analysis from position: 8
1 jumps found. (Code = 42) Position 1 = 11
Branch analysis from position: 11
2 jumps found. (Code = 43) Position 1 = 16, Position 2 = 18
Branch analysis from position: 16
1 jumps found. (Code = 42) Position 1 = 19
Branch analysis from position: 19
1 jumps found. (Code = 62) Position 1 = -2
Branch analysis from position: 18
1 jumps found. (Code = 62) Position 1 = -2
Branch analysis from position: 10
2 jumps found. (Code = 43) Position 1 = 16, Position 2 = 18
Branch analysis from position: 16
Branch analysis from position: 18
filename:       /in/4JnBH
function name:  (null)
number of ops:  20
compiled vars:  !0 = $nullvar
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    3     0  E >   FETCH_DIM_W                                      $1      !0, 0
          1        FETCH_DIM_W                                      $2      $1, 'a'
          2        ASSIGN_DIM                                               $2, 'r'
          3        OP_DATA                                                  null
    6     4        FETCH_DIM_IS                                     ~4      !0, 0
          5        FETCH_DIM_IS                                     ~5      ~4, 'a'
          6        ISSET_ISEMPTY_DIM_OBJ                         0          ~5, 'r'
          7      > JMPZ                                                     ~6, ->10
    7     8    >   ECHO                                                     'set'
          9      > JMP                                                      ->11
    9    10    >   ECHO                                                     'not+set'
   12    11    >   FETCH_DIM_R                                      ~7      !0, 0
         12        FETCH_DIM_R                                      ~8      ~7, 'a'
         13        FETCH_DIM_R                                      ~9      ~8, 'r'
         14        TYPE_CHECK                                    2          ~9
         15      > JMPZ                                                     ~10, ->18
   13    16    >   ECHO                                                     '%0Anull'
         17      > JMP                                                      ->19
   15    18    >   ECHO                                                     '%0Anot+null'
   16    19    > > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 8.0.0


preferences:
146.58 ms | 1394 KiB | 13 Q