Ruby: String

intro

• strings are a sequences of characters.
• the name comes from the fact that the characters are strung together.

string format

• single quoted ('string') : basic string, faster than double quoted.
• double quoted ("string") : support interpolation and escape sequences.
• back quoted (`string`): execute as command in bin/rails folder.
• other.%q quoted (%q(foo bar): string without interpolation.
• other.%Q quoted (%Q(foo #{bar})): string with interpolation.

fancy way

• concate: 'foo' << 'bar'
• multiply: 'foo' * 1000
• 'aaa'.next #=> 'aab'
• '111'.next #=> '112'

search methods

• check whether a string contains any given character or substring.
• e.g.: #include?, #start_with?. #end_with?, #index, etc...

case change methods

• e.g.: #upcase, #downcase, #swapcase, #capitalize, etc...

split methods

• split strings by particular characters.
• e.g. combine #split and regex to operate.
• like split strings on newlines, and parse date in csv.

concatenate methods

• create new string by adding two string together.
• efficiency: '<<' same as '#concat' better than '+'
• << and #concat change the original string object.

replace substring

• first search for substrings or use regex.
• e.g.: #sub(a, b); #gsub(a, b); #gsub(/regex/, b);
• regex are a concise and flex means for 'matching' strings.
• if you want to implement a parser, #match might be a good friend :P

chop and chomp

• todo