Conversion of decimal and hexadecimal in PHP

{Code...} convert hexadecimal format $ s to decimal format and convert it back to hexadecimal format. There is a limit on the size of dechex () conversion. ------------ Supplement --------------------------------------- $ s & #039; 9C216AFB868C & #039; How does $ s add 1php ?...

$s = '9C216AFB868C';$sb=hexdec($s) ;var_dump( $sb );//1.716673427227E+14echo '
';var_dump( dechex($sb) );//6afb868c

Convert the hexadecimal value $ s to the decimal value, and then convert the hexadecimal value to the hexadecimal value.

Querydechex()The conversion size is limited.
------------ Supplement ---------------------------------------
$ S = '9c216afb868c ';
How is it implemented in $ s plus 1 php? (Hexadecimal calculation)

Reply content:

$s = '9C216AFB868C';$sb=hexdec($s) ;var_dump( $sb );//1.716673427227E+14echo '
';var_dump( dechex($sb) );//6afb868c

Convert the hexadecimal value $ s to the decimal value, and then convert the hexadecimal value to the hexadecimal value.

Querydechex()The conversion size is limited.
------------ Supplement ---------------------------------------
$ S = '9c216afb868c ';
How is it implemented in $ s plus 1 php? (Hexadecimal calculation)

The final output result can be compared.6afb868cExactly9C216AFB868C(Case Insensitive ).

In the hexdec manual ,:

Starting from PHP 4.1.0, this function can process large integer numbers. In this case, it will return the float type.

In dechex:

The maximum value to be converted is decimal.PHP_INT_MAX * 2 + 1(Or-1): On a 32-bit platform, the decimal value is 4294967295, and the result of dechex () isFfffffff.

First result1.716673427227E+14Common Format171667342722700, There is no problem with this result.

9c216afb868cTo decimal: http://www.wolframalpha.com/input? I = convert ++ 9c216afb868c + to + base + 10

This number is converted back to Yes9c216afb868c.

171667342722700Turn hexadecimal: http://www.wolframalpha.com/input? I = 171667342722700 + to + hex

First, if you are not a 32-bit computer, the number of digits is far from the maximum number that PHP can handle. The maximum value in PHP can be a constant.PHP_INT_MAXThe value of the 64-bit computer is

echo PHP_INT_MAX;    // 9223372036854775807echo dechex(PHP_INT_MAX); // 7fffffffffffffff

Besides, you can switch from hexadecimal to hexadecimal.It's impossible to go back because of the size problem.. The problem lies in the 10 hexadecimal value you transferred out. It is

1.716673427227E+14

This isString represented by scientific notation, AnddechexThe function cannot recognize this string,In php, only strings composed of numbers are automatically converted to corresponding integer or floating point values..