Slides
String Messages
A string understands lots of messages. Here are a few:
"banana".upcase
"Cherry".downcase
"titanic".capitalize
"elderberry".reverse
"fig".length
"Fig Newton".swapcase
"".empty?
"syzygy".length
Try all of these out in irb!
String Operators
A string knows DOT, but also understands several other operators:
"blue" + "berry"
"yum" * 10
"elderberry"[8]
+
*
and []
are pronounced PLUS, TIMES, and SUB
Try these out in irb!
Combining Messages and Operators
You can combine messages and operators at will.
"fig".upcase.reverse
"grape".reverse * 10 + "!!!"
Definitely try these out in irb! It's pretty fun.
LAB: Playing With Strings
- What is the reverse of "stressed"?
- How many characters long is your name?
- What does your name look like, repeated 1000 times?
- What is the tenth character of "Matz is nice"? (Trick question!)
Interpolation
first = "Joe"
last = "Smith"
+
does concatenation
full = first + " " + last
#{}
does interpolation
full = "#{first} #{last}"