hash
Construct a hash value from a string value using either the md5 or sha256 algorithm.
Examples:
hash('test', 'sha256')
-- Result: "9F86D081884C7D659A2FEAA0C55AD015A3BF4F1B2B0B822CD15D6C15B0F00A08"
hash('test', 'md5')
-- Result: "098F6BCD4621D373CADE4E832627B4F6"
text, text -> text