PHP crc32() Function
The PHP crc32() function generates the cyclic redundancy checksum polynomial of 32-bit lengths of the string. This is usually used to validate the integrity of data being transmitted.
Note: As PHP's integer type is signed, therefore many crc32() checksums will result in negative integers on 32bit platforms. On 64bit installations all crc32() results will be positive integers though.
The %u formatter of the printf() or sprintf() function should be used to get the correct string representation of the unsigned crc32() checksum in decimal format. If the %u formatter is not used, the result may display in incorrect and negative numbers.
For a hexadecimal representation of the checksum, the "%x" formatter of sprintf() or printf() or the dechex() conversion functions can be used.Syntax
crc32(str)
Parameters
str |
Required. Specify the string to be calculated. |
Return Value
Returns the crc32 checksum of string as an integer.
Example: crc32() example
In the example below shows the usage of crc32() function.
<?php
$str = "Hello World!";
$checksum = crc32($str);
printf("%u",$checksum);
?>
The output of the above code will be:
472456355
❮ PHP String Reference
