3v4l.org

run code in 300+ PHP versions simultaneously
<?php function &bar() { $bar = null; return $bar; } // vs function &bar2() { return null; } var_dump(bar(1)); var_dump(bar2(1));
Finding entry points
Branch analysis from position: 0
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/EOupL
function name:  (null)
number of ops:  13
compiled vars:  none
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
   15     0  E >   INIT_FCALL                                               'var_dump'
          1        INIT_FCALL                                               'bar'
          2        SEND_VAL                                                 1
          3        DO_FCALL                                      0  $0      
          4        SEND_VAR                                                 $0
          5        DO_ICALL                                                 
   16     6        INIT_FCALL                                               'var_dump'
          7        INIT_FCALL                                               'bar2'
          8        SEND_VAL                                                 1
          9        DO_FCALL                                      0  $2      
         10        SEND_VAR                                                 $2
         11        DO_ICALL                                                 
         12      > RETURN                                                   1

Function bar:
Finding entry points
Branch analysis from position: 0
Return found
filename:       /in/EOupL
function name:  bar
number of ops:  3
compiled vars:  !0 = $bar
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    4     0  E >   ASSIGN                                                   !0, null
    6     1      > RETURN_BY_REF                                            !0
    7     2*     > RETURN_BY_REF                                            null

End of function bar

Function bar2:
Finding entry points
Branch analysis from position: 0
Return found
filename:       /in/EOupL
function name:  bar2
number of ops:  2
compiled vars:  none
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
   12     0  E > > RETURN_BY_REF                                            null
   13     1*     > RETURN_BY_REF                                            null

End of function bar2

Generated using Vulcan Logic Dumper, using php 8.0.0


preferences:
178.46 ms | 1397 KiB | 17 Q