Variables hold data and data types define the kind of data a variable can hold.
# variable declaration
x = 10
# data types
string = "hello"
integer = 42
float = 3.14
boolean = true
array = [1, 2, 3]
hash = { name: "John", age: 25 }
Functions are reusable code blocks that take input parameters and perform a set of instructions.
# function declaration
def greet(name)
puts "Hello, #{name}!"
end
# function call
greet("John")
Loops allow you to repeatedly execute code.
# while loop
i = 0
while i < 5 do
puts i
i += 1
end
# for loop
for i in 0..4
puts i
end
# each loop
[1, 2, 3].each do |i|
puts i
end
Conditionals execute code based on whether a condition is true or false.
# if statement
x = 10
if x > 5
puts "x is greater than 5"
end
# else statement
if x < 5
puts "x is less than 5"
else
puts "x is greater than or equal to 5"
end
# case statement
grade = "A"
case grade
when "A"
puts "Great job!"
when "B"
puts "Good job!"
else
puts "Try harder next time!"
end
Reading and writing files is a common task in programming.
# writing to a file
File.open("file.txt", "w") do |file|
file.write("Hello, world!")
end
# reading from a file
File.open("file.txt", "r") do |file|
puts file.read
end
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