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<?php $arr = []; $arr['key'] = NULL; var_dump(isset($arr['key'])); //bool(false) var_dump(is_null($arr['key'])); //bool(true) var_dump(is_null($arr['any_key']));
Finding entry points
Branch analysis from position: 0
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/g5d1V
function name:  (null)
number of ops:  18
compiled vars:  !0 = $arr
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    3     0  E >   ASSIGN                                                   !0, <array>
    4     1        ASSIGN_DIM                                               !0, 'key'
          2        OP_DATA                                                  null
    6     3        INIT_FCALL                                               'var_dump'
          4        ISSET_ISEMPTY_DIM_OBJ                         0  ~3      !0, 'key'
          5        SEND_VAL                                                 ~3
          6        DO_ICALL                                                 
    9     7        INIT_FCALL                                               'var_dump'
          8        FETCH_DIM_R                                      ~5      !0, 'key'
          9        TYPE_CHECK                                    2  ~6      ~5
         10        SEND_VAL                                                 ~6
         11        DO_ICALL                                                 
   12    12        INIT_FCALL                                               'var_dump'
         13        FETCH_DIM_R                                      ~8      !0, 'any_key'
         14        TYPE_CHECK                                    2  ~9      ~8
         15        SEND_VAL                                                 ~9
         16        DO_ICALL                                                 
         17      > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 8.0.0


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