Working with Strings in Ruby

Strings are a common data type we find and use in many programming languages.

As we are used to using Strings, we find that there are several common methods/functions for working with strings. Some we’ve already seen, but here are also some new ones.

size: the size operator lets us see how big a string is.

puts "Hello".size # prints 5

upcase: converts a string to all upper case

puts "Hello".upcase # prints HELLO

downcase: converts a string to all lower case characters

puts "Hello".downcase # prints hello

swapcase: swaps the case of the letters with in a string

puts "Hello".swapcase # prints hELLO

chars: converts a string to an array of letters

puts "Hello".chars

-begin 
Prints out
H
e
l
l
o
-end

gsub: substitute a series of characters for another

puts "Hello".gsub("ello","i") # prints Hi

to_i and to_f converts a string to an integer number.

puts "1".to_i   # prints 1
puts "1.1".to_i # prints 1 - notice it drops the decimal value

puts "1".to_f   # prints 1.0
puts "1.1".to_f # prints 1.1

String Concatenation

Strings are concatenated in Ruby with the plus (+) symbol.

answer = "1" + "1" 
# answer is now "11"

Ruby will not try to convert data-types to concatenate like JavaScript, so the following example will yield an error:

puts "1" + 1 # error in type conversion

String Interpolation

You can build more complex strings by inserting values into your string. To do so, you will have a #{<variable name>} inside of your string. This will be replaced by whatever the value of the variable is. Note that you can change data types, and it doesn’t matter.

age = 20
name = "David"

puts "Hello #{name}, you are #{age} years old."

Working with Strings in Ruby was originally found on Access 2 Learn