Operators

In Ruby, you have 9 main categories of operators:

• Arithmetic Operators
• Comparison Operators
• Assignment Operators
• Logical Operators
• Bitwise Operators
• Ternary Operator
• Range Operators
• Membership Operators
• Defined Operator

Arithmetic Operators

Arithmetic operators are used for performing mathematical operations on numeric values.

# Addition
result_addition = 5 + 3.0
puts result_addition  # => 8.0

# Subtraction
result_subtraction = 7 - 2
puts result_subtraction  # => 5

# Multiplication
result_multiplication = 4 * 6.0
puts result_multiplication  # => 24.0

# Division
result_division = 15 / 3
puts result_division  # => 5

# Modulus (remainder after division)
result_modulus = 17 % 5
puts result_modulus  # => 2

# Exponentiation
result_exponentiation = 2**3
puts result_exponentiation  # => 8

Comparison Operators

Comparison operators in Ruby are used to compare values and return a boolean result.

# Equal to
puts 5 == 5   # true

# Not equal to
puts 5 != 3   # true

# Less than
puts 3 < 5    # true

# Greater than
puts 5 > 3    # true

# Less than or equal to
puts 3 <= 5   # true

# Greater than or equal to
puts 5 >= 3   # true

Assignment Operators

Assignment operators in Ruby are used to assign values to variables.

# Assignment
x = 5
puts x  # => 5

# Add and assign
x += 3
puts x  # => 8

# Subtract and assign
x -= 2
puts x  # => 6

# Multiply and assign
x *= 4
puts x  # => 24

# Divide and assign
x /= 3
puts x  # => 8

Logical Operators

Logical operators are used to perform logical operations between boolean values.

# Logical AND
result_and = true && false
puts result_and  # => false

# Logical OR
result_or = true || false
puts result_or  # => true

# Logical NOT
result_not = !true
puts result_not  # => false

Bitwise Operators

Bitwise operators in Ruby are used for manipulation of individual bits in integer values.

# Bitwise AND
result_and = 5 & 3
puts result_and  # => 1

# Bitwise OR
result_or = 5 | 3
puts result_or  # => 7

# Bitwise XOR (exclusive OR)
result_xor = 5 ^ 3
puts result_xor  # => 6

# Bitwise NOT (complement)
result_not = ~5
puts result_not  # => -6

# Left shift
result_left_shift = 5 << 2
puts result_left_shift  # => 20

# Right shift
result_right_shift = 5 >> 1
puts result_right_shift  # => 2

Ternary Operator

The ternary operator in Ruby is a concise way to write a simple conditional expression. The basic syntax is just like C's:

condition ? expression_if_true : expression_if_false

Here's an example:

age = 20
result = (age >= 18) ? "Adult" : "Minor"
puts result  # => "Adult"

Range Operators

In Ruby, the range operator is used to create ranges of values. There are two types of range operators: inclusive range (..) and exclusive range (...).

inclusive_range = 1..5

# Convert the range to an array
puts inclusive_range.to_a.inspect  # => [1, 2, 3, 4, 5]


exclusive_range = 1...5

# Convert the range to an array
puts exclusive_range.to_a.inspect  # => [1, 2, 3, 4]

Membership Operators

Membership operators are used to check if an element belongs to a collection.

in?

The in? operator checks if an element is present in a collection:

fruits = ["apple", "banana", "orange"]

puts "banana".in?(fruits)  # true
puts "grape".in?(fruits)   # false

!in?

The !in? operator checks if an element is not present in a collection:

fruits = ["apple", "banana", "orange"]

puts "banana".!in?(fruits)  # false
puts "grape".!in?(fruits)   # true

Defined Operator

The defined? operator is used to check if a given variable, method, or block is defined. It returns a string describing the type of the entity if it is defined, and nil otherwise.

x = 58

if defined?(x)
  puts "Variable x is defined."
else
  puts "Variable x is not defined."
end

Code Challenge

Write a Ruby function that takes an integer as input and returns the count of set bits (1s) in its binary representation. Use bitwise operators to implement this function.