Generates the cyclic redundancy checksum polynomial of 32-bit
lengths of the
str. This is usually used
to validate the integrity of data being transmitted.
Because PHP's integer type is signed, and many crc32 checksums will result in negative integers, you need to use the "%u" formatter of sprintf() or printf() to get the string representation of the unsigned crc32 checksum.
This second example shows how to print a converted checksum with the printf() function: