Interprets EXPR as a hex string and returns the corresponding numeric value. If EXPR is omitted, uses $_
.
print hex '0xAf'; # prints '175'
print hex 'aF'; # same
$valid_input =~ /\A(?:0?[xX])?(?:_?[0-9a-fA-F])*\z/
A hex string consists of hex digits and an optional 0x
or x
prefix. Each hex digit may be preceded by a single underscore, which will be ignored. Any other character triggers a warning and causes the rest of the string to be ignored (even leading whitespace, unlike oct
). Only integers can be represented, and integer overflow triggers a warning.
To convert strings that might start with any of 0
, 0x
, or 0b
, see oct
. To present something as hex, look into printf
, sprintf
, and unpack
.