Returns the decimal equivalent of the hexadecimal number
represented by the
hex_string argument.
hexdec() converts a hexadecimal string to a decimal
number. The largest number that can be converted is 7fffffff
or 2147483647 in decimal.
hexdec() will replace of any
non-hexadecimal characters it encounters by 0. This way, all left zeros are ignored, but
right zeros will be valued.
See also dechex().