3v4l.org

run code in 300+ PHP versions simultaneously
<?php var_dump(substr('', 0, 0)); var_dump(substr('', 0, 1)); var_dump(substr('', 0, 2)); var_dump(substr('a', 0, 0)); var_dump(substr('a', 0, 1)); var_dump(substr('a', 0, 2)); var_dump(substr('ab', 0, 0)); var_dump(substr('ab', 0, 1)); var_dump(substr('ab', 0, 2));
Finding entry points
Branch analysis from position: 0
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/ATijm
function name:  (null)
number of ops:  73
compiled vars:  none
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    2     0  E >   INIT_FCALL                                               'var_dump'
          1        INIT_FCALL                                               'substr'
          2        SEND_VAL                                                 ''
          3        SEND_VAL                                                 0
          4        SEND_VAL                                                 0
          5        DO_ICALL                                         $0      
          6        SEND_VAR                                                 $0
          7        DO_ICALL                                                 
    3     8        INIT_FCALL                                               'var_dump'
          9        INIT_FCALL                                               'substr'
         10        SEND_VAL                                                 ''
         11        SEND_VAL                                                 0
         12        SEND_VAL                                                 1
         13        DO_ICALL                                         $2      
         14        SEND_VAR                                                 $2
         15        DO_ICALL                                                 
    4    16        INIT_FCALL                                               'var_dump'
         17        INIT_FCALL                                               'substr'
         18        SEND_VAL                                                 ''
         19        SEND_VAL                                                 0
         20        SEND_VAL                                                 2
         21        DO_ICALL                                         $4      
         22        SEND_VAR                                                 $4
         23        DO_ICALL                                                 
    5    24        INIT_FCALL                                               'var_dump'
         25        INIT_FCALL                                               'substr'
         26        SEND_VAL                                                 'a'
         27        SEND_VAL                                                 0
         28        SEND_VAL                                                 0
         29        DO_ICALL                                         $6      
         30        SEND_VAR                                                 $6
         31        DO_ICALL                                                 
    6    32        INIT_FCALL                                               'var_dump'
         33        INIT_FCALL                                               'substr'
         34        SEND_VAL                                                 'a'
         35        SEND_VAL                                                 0
         36        SEND_VAL                                                 1
         37        DO_ICALL                                         $8      
         38        SEND_VAR                                                 $8
         39        DO_ICALL                                                 
    7    40        INIT_FCALL                                               'var_dump'
         41        INIT_FCALL                                               'substr'
         42        SEND_VAL                                                 'a'
         43        SEND_VAL                                                 0
         44        SEND_VAL                                                 2
         45        DO_ICALL                                         $10     
         46        SEND_VAR                                                 $10
         47        DO_ICALL                                                 
    8    48        INIT_FCALL                                               'var_dump'
         49        INIT_FCALL                                               'substr'
         50        SEND_VAL                                                 'ab'
         51        SEND_VAL                                                 0
         52        SEND_VAL                                                 0
         53        DO_ICALL                                         $12     
         54        SEND_VAR                                                 $12
         55        DO_ICALL                                                 
    9    56        INIT_FCALL                                               'var_dump'
         57        INIT_FCALL                                               'substr'
         58        SEND_VAL                                                 'ab'
         59        SEND_VAL                                                 0
         60        SEND_VAL                                                 1
         61        DO_ICALL                                         $14     
         62        SEND_VAR                                                 $14
         63        DO_ICALL                                                 
   10    64        INIT_FCALL                                               'var_dump'
         65        INIT_FCALL                                               'substr'
         66        SEND_VAL                                                 'ab'
         67        SEND_VAL                                                 0
         68        SEND_VAL                                                 2
         69        DO_ICALL                                         $16     
         70        SEND_VAR                                                 $16
         71        DO_ICALL                                                 
         72      > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 8.0.0


preferences:
267.01 ms | 1400 KiB | 18 Q