散列函数不仅返回小写字母和数字，还返回符号和大写字母

Question

All hash algorithms (sha1, md5 etc) seem to return string with lowercase letters and numbers. Are there any algorithms which also return symbols like [ ] \ , ! etc. and uppercase letters?

Answer 1

A typical hash function (like MD5) produces bytes as output. These bytes are usually hex encoded so that they can be represented as text. However, there are other binary-to-text encodings too.