3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $a = ''; $b = 'hello'; if(isset($a['hello'])){ print 'Empty'; }
Finding entry points
Branch analysis from position: 0
Jump found. Position 1 = 4, Position 2 = 5
Branch analysis from position: 4
Jump found. Position 1 = -2
Branch analysis from position: 5
filename:       /in/dEmsK
function name:  (null)
number of ops:  6
compiled vars:  !0 = $a, !1 = $b
line     #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
   2     0  E >   ASSIGN                                                   !0, ''
   3     1        ASSIGN                                                   !1, 'hello'
   4     2        ISSET_ISEMPTY_DIM_OBJ                       33554432  ~4      !0, 'hello'
         3      > JMPZ                                                     ~4, ->5
   5     4    >   ECHO                                                     'Empty'
         5    > > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 7.2.0