Convert big integer or float to string exactly as they are

Question

pay attention the integer is bigger than PHP_INT_MAX (9223372036854775807)

Code:

  $x = 1502648031311810478;
  var_dump($x);

Output:

float 1.502648031381E+16

I want this:

1502648031311810478

as a string.

I tried all ways of casting but output is 1.502648031381E+16

I want exact integer in string.

This is not a duplicate of Converting an integer to a string in PHP because none of the answers to that question cover the case when the number is outside PHP_INT_MAX.

@MadhurBhaiya try it with another 0. There seems to be a comment [here](http://php.net/manual/en/function.intval.php#61292) without a solution. — Nigel Ren, Nov 12 '18 at 07:54
@AlivetoDie it is not a Dupe. None of the answers in the duplicate marked link cover the case when the number is outside `PHP_INT_MAX`. — Madhur Bhaiya, Nov 12 '18 at 08:02
@AlivetoDie agreed that OP's example is wrong. But his idea for asking this on right track. Please check the discussion above. — Madhur Bhaiya, Nov 12 '18 at 08:05
Where exactly is the number coming from? The question cannot be answered properly without this information. — Salman A, Nov 12 '18 at 08:13
@SalmanA this is the number that i want to save to db to use somewhere else but i need exact number to use. something like it's pointer — Mohsen, Nov 12 '18 at 08:24
@mohsen apparently you're using 32-bit PHP so it cannot represent this number as int, it will be auto-converted to float. You can specify the number as string though `$x = '1502648031311810478';` which is why I asked where it comes from. — Salman A, Nov 12 '18 at 08:27
@SalmanA i use 64bit php and number come from some web service that use this long number as pointer to other methods and i just want to save it and use it in future. — Mohsen, Nov 12 '18 at 08:30
@mohsen is it coming as json (and you're running json_decode on it)? And are you sure about PHP being 64 bit (check `echo PHP_INT_MAX;` and post what it returns) — Salman A, Nov 12 '18 at 08:36
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/183489/discussion-between-salman-a-and-mohsen). — Salman A, Nov 12 '18 at 09:46

score 3 · Accepted Answer · answered Nov 12 '18 at 10:21

Seems like you're using json_decode. It will convert numbers to integers where possible, otherwise float:

// 32bit integers
var_dump(json_decode("2147483647")); // int(2147483647)
var_dump(json_decode("2147483648")); // float(2147483648)

// 64bit integers
var_dump(json_decode("9223372036854775807")); // int(9223372036854775807)
var_dump(json_decode("9223372036854775808")); // float(9.2233720368548E+18)

You can use JSON_BIGINT_AS_STRING flag so that json_decode decodes large integers as their original string value:

// 32bit integers
var_dump(json_decode("2147483647", false, 512, JSON_BIGINT_AS_STRING)); // int(2147483647)
var_dump(json_decode("2147483648", false, 512, JSON_BIGINT_AS_STRING)); // string(10) "2147483648"
// 64bit integers
var_dump(json_decode("9223372036854775807", false, 512, JSON_BIGINT_AS_STRING)); // int(9223372036854775807)
var_dump(json_decode("9223372036854775808", false, 512, JSON_BIGINT_AS_STRING)); // string(19) "9223372036854775808"

Note that the number-as-a-string is not really useful for arithmetic e.g. you cannot add or multiply from it without it (auto) converting to float.

Convert big integer or float to string exactly as they are

1 Answers1