Ruby in 100 Minutes

####string gotcha

Ruby can’t do string + num

Use .to_s to get around it

Or maybe use this:

number = 4
puts "print a number: #{number}"

####Symbols

• Starts with a colon then one or more letters
• Less methods than Strings

####Iterating

Use times method to repeat an instruction

5.times do
  ...
end

####Arrays

• Return nil when index out of range
• << operator for appending a signle element
• Elements don’t need to be of same type

####Hashes

• { key => value ... }
• methods: keys, values

• simplified syntax when all keys are symbols:

  { symbol: value ... }

  (for Ruby 1.9 and higher)

####Conditionals

method name ending in a ?: return true or false

####chomp

• get rid of the Enter
• gets.chomp

####exponentiation

**

5**2

####random

• rand(1) always produce 0
• rand(101): 0-100
• srand
• srand 0 seed with current time in ms

####block as a parameter

• precede the parameter with an ampersand(&)

####global variable

• preced the variable with $