Introduction to Comparison Operators

What Are Comparison Operators?

• Tools to compare two values.
• Example:
  • int x = 15;
  • int y = 10;
  • boolean z = x > y; (results in true because 15 is greater than 10)

Types of Comparison Operators

• Equal to: ==
• Not equal to: !=
• Less than: <
• Greater than: >
• Less than or equal to: <=
• Greater than or equal to: >=

Usage

• Used to compare primitive types: int, double, boolean, char
• Not typically used for strings (more complex)

Example Scenarios

Roller Coaster Height Check

• Input: int heightInInches = readInt("What is your height?");
• Logic: boolean canRide = heightInInches >= 50;
  • Determines if the user can ride based on being at least 50 inches tall.

Grade Evaluation

• Input: int grade = readInt("What was your grade?");
• Boolean: boolean gotB = (grade >= 80) && (grade < 90);
  • Checks if a grade is between 80 and 90.

Code Demonstration

• Input Grade:

  int grade = readInt("What was your grade?");
  boolean gotB = (grade >= 80) && (grade < 90);
  System.out.println("Got a B: " + gotB);
  

• Test Cases:
  • Grade 85: true (B-grade)
  • Grade 80: true (B-grade, edge case)
  • Grade 90: false (not a B)
  • Grade 74: false (not a B)

Key Takeaways

• Comparison operators allow for the evaluation of relationships between values.
• Logical operators like AND (&&) are used to combine comparison conditions.
• Practical application includes determining eligibility or classifications based on input values.