Ruby Numbers

Number Types

count = 42
year = 2024

price = 19.99
pi = 3.14159

10 + 5   # 15
10 * 5   # 50

42.to_f  # 42.0
3.14.to_i # 3

🔹 Integer Numbers

Integers are whole numbers without decimal points. Ruby automatically handles both small and very large integers efficiently.

# Integer examples
age = 25
year = 2024
negative = -10
large = 1_000_000_000  # Underscores for readability

puts age              # Output: 25
puts negative         # Output: -10
puts large            # Output: 1000000000
puts age.class        # Output: Integer

25
-10
1000000000
Integer

🔹 Floating-Point Numbers

Floats represent decimal numbers. They're essential for precise calculations involving fractions and measurements.

# Float examples
price = 19.99
temperature = -5.5
pi = 3.14159
scientific = 1.5e3  # Scientific notation (1500.0)

puts price            # Output: 19.99
puts temperature      # Output: -5.5
puts scientific       # Output: 1500.0
puts price.class      # Output: Float

19.99
-5.5
1500.0
Float

🔹 Basic Arithmetic Operations

Perform mathematical calculations using standard arithmetic operators. Ruby follows standard mathematical precedence rules.

# Arithmetic operations
a = 20
b = 5

puts a + b    # Addition: 25
puts a - b    # Subtraction: 15
puts a * b    # Multiplication: 100
puts a / b    # Division: 4
puts a % b    # Modulus (remainder): 0
puts a ** b   # Exponentiation: 3200000

25
15
100
4
0
3200000

🔹 Integer vs Float Division

Division behavior differs between integers and floats. Integer division returns an integer, while float division returns a decimal result.

# Integer division
puts 10 / 3       # Output: 3 (integer result)
puts 10 / 4       # Output: 2

# Float division
puts 10.0 / 3     # Output: 3.3333333333333335
puts 10 / 3.0     # Output: 3.3333333333333335
puts 10.0 / 4.0   # Output: 2.5

# Convert to float for decimal result
puts 10.to_f / 3  # Output: 3.3333333333333335

3
2
3.3333333333333335
3.3333333333333335
2.5
3.3333333333333335

🔹 Number Conversion

Convert between different numeric types using conversion methods. Ruby provides simple methods for type conversion.

# Integer to Float
num = 42
puts num.to_f         # Output: 42.0

# Float to Integer (truncates decimal)
price = 19.99
puts price.to_i       # Output: 19

# String to Number
text = "100"
puts text.to_i        # Output: 100
puts text.to_f        # Output: 100.0

# Number to String
age = 25
puts age.to_s         # Output: "25"

42.0
19
100
100.0
25

🔹 Number Methods

Ruby provides many useful methods for working with numbers, including rounding, absolute values, and mathematical operations.

# Useful number methods
num = -15.7

puts num.abs          # Absolute value: 15.7
puts num.round        # Round: -16
puts num.floor        # Floor: -16
puts num.ceil         # Ceiling: -15

# Even and odd
puts 10.even?         # Output: true
puts 10.odd?          # Output: false
puts 7.even?          # Output: false
puts 7.odd?           # Output: true

15.7
-16
-16
-15
true
false
false
true

🔹 Number Ranges

Create sequences of numbers using ranges. Ranges are useful for loops and generating number sequences.

# Number ranges
range1 = (1..5)       # Inclusive (includes 5)
range2 = (1...5)      # Exclusive (excludes 5)

puts range1.to_a.inspect   # Output: [1, 2, 3, 4, 5]
puts range2.to_a.inspect   # Output: [1, 2, 3, 4]

# Using ranges in loops
(1..3).each do |i|
  puts i
end
# Output: 1, 2, 3

[1, 2, 3, 4, 5]
[1, 2, 3, 4]
1
2
3

🔹 Random Numbers

Generate random numbers using the rand method. Useful for games, simulations, and random selections.

# Random numbers
puts rand           # Random float between 0 and 1
puts rand(10)       # Random integer from 0 to 9
puts rand(1..6)     # Random integer from 1 to 6 (dice roll)

# Random float in range
puts rand * 100     # Random float from 0 to 100

# Example: Dice roll
dice = rand(1..6)
puts "You rolled: #{dice}"

0.6789
7
4
45.23
You rolled: 3

🔹 Math Module

Ruby's Math module provides advanced mathematical functions like square root, trigonometry, and logarithms.

# Math module functions
puts Math.sqrt(16)        # Square root: 4.0
puts Math.sqrt(2)         # Output: 1.4142135623730951

puts Math::PI             # Pi constant: 3.141592653589793
puts Math::E              # Euler's number: 2.718281828459045

# Trigonometry
puts Math.sin(0)          # Output: 0.0
puts Math.cos(0)          # Output: 1.0

# Power and logarithm
puts Math.log(10)         # Natural log: 2.302585092994046
puts Math.log10(100)      # Base 10 log: 2.0

4.0
1.4142135623730951
3.141592653589793
2.718281828459045
0.0
1.0
2.302585092994046
2.0