3v4l.org

run code in 500+ PHP versions simultaneously
<?php function isJson($string) { $decoded = json_decode($string); return (json_last_error() == JSON_ERROR_NONE); } if ( isJson("hello") ) { echo "valid JSON"; } else { echo "not valid JSON"; }
Finding entry points
Branch analysis from position: 0
2 jumps found. (Code = 43) Position 1 = 4, Position 2 = 6
Branch analysis from position: 4
1 jumps found. (Code = 42) Position 1 = 7
Branch analysis from position: 7
1 jumps found. (Code = 62) Position 1 = -2
Branch analysis from position: 6
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/lSsEo
function name:  (null)
number of ops:  8
compiled vars:  none
line      #* E I O op                               fetch          ext  return  operands
-----------------------------------------------------------------------------------------
    8     0  E >   INIT_FCALL                                                   'isjson'
          1        SEND_VAL                                                     'hello'
          2        DO_FCALL                                          0  $0      
          3      > JMPZ                                                         $0, ->6
    9     4    >   ECHO                                                         'valid+JSON'
    8     5      > JMP                                                          ->7
   11     6    >   ECHO                                                         'not+valid+JSON'
   12     7    > > RETURN                                                       1

Function isjson:
Finding entry points
Branch analysis from position: 0
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/lSsEo
function name:  isJson
number of ops:  10
compiled vars:  !0 = $string, !1 = $decoded
line      #* E I O op                               fetch          ext  return  operands
-----------------------------------------------------------------------------------------
    3     0  E >   RECV                                                 !0      
    4     1        INIT_FCALL                                                   'json_decode'
          2        SEND_VAR                                                     !0
          3        DO_ICALL                                             $2      
          4        ASSIGN                                                       !1, $2
    5     5        INIT_FCALL                                                   'json_last_error'
          6        DO_ICALL                                             $4      
          7        IS_EQUAL                                             ~5      $4, 0
          8      > RETURN                                                       ~5
    6     9*     > RETURN                                                       null

End of function isjson

Generated using Vulcan Logic Dumper, using php 8.5.0


preferences:
166.71 ms | 2282 KiB | 16 Q