3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = null; print $a ?? 'b'; print "\n"; print $a ?: 'b'; print "\n"; print $c ?? 'a'; print "\n"; print $c ?: 'a'; print "\n";
Finding entry points
Branch analysis from position: 0
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/nZDFs
function name:  (null)
number of ops:  18
compiled vars:  !0 = $a, !1 = $c
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    3     0  E >   ASSIGN                                                   !0, null
    5     1        COALESCE                                         ~3      !0
          2        QM_ASSIGN                                        ~3      'b'
          3        ECHO                                                     ~3
    6     4        ECHO                                                     '%0A'
    8     5        JMP_SET                                          ~4      !0, ->7
          6        QM_ASSIGN                                        ~4      'b'
          7        ECHO                                                     ~4
    9     8        ECHO                                                     '%0A'
   11     9        COALESCE                                         ~5      !1
         10        QM_ASSIGN                                        ~5      'a'
         11        ECHO                                                     ~5
   12    12        ECHO                                                     '%0A'
   14    13        JMP_SET                                          ~6      !1, ->15
         14        QM_ASSIGN                                        ~6      'a'
         15        ECHO                                                     ~6
   15    16        ECHO                                                     '%0A'
         17      > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 8.0.0


preferences:
161.8 ms | 1393 KiB | 13 Q