Relational operators in C++ are used to compare two values or expressions and return a boolean result, either true or false. They are essential for control flow in programs, especially in conditional statements and loops. Here’s a detailed explanation of the different relational operators available in C++:

1. Equal to Operator (==)

This operator checks if two operands are equal.

• Syntax:

  operand1 == operand2
  

• Example:

  #include <iostream>
  
  int main() {
      int a = 5, b = 5;
      bool isEqual = (a == b); // isEqual is true
      std::cout << "a is equal to b: " << std::boolalpha << isEqual << std::endl;
      return 0;
  }
  

2. Not Equal to Operator (!=)

This operator checks if two operands are not equal.

• Syntax:

  operand1 != operand2
  

• Example:

  #include <iostream>
  
  int main() {
      int a = 5, b = 3;
      bool isNotEqual = (a != b); // isNotEqual is true
      std::cout << "a is not equal to b: " << std::boolalpha << isNotEqual << std::endl;
      return 0;
  }
  

3. Greater than Operator (>)

This operator checks if the left operand is greater than the right operand.

• Syntax:

  operand1 > operand2
  

• Example:

  #include <iostream>
  
  int main() {
      int a = 7, b = 5;
      bool isGreater = (a > b); // isGreater is true
      std::cout << "a is greater than b: " << std::boolalpha << isGreater << std::endl;
      return 0;
  }
  

4. Less than Operator (<)

This operator checks if the left operand is less than the right operand.

• Syntax:

  operand1 < operand2
  

• Example:

  #include <iostream>
  
  int main() {
      int a = 4, b = 6;
      bool isLess = (a < b); // isLess is true
      std::cout << "a is less than b: " << std::boolalpha << isLess << std::endl;
      return 0;
  }
  

5. Greater than or Equal to Operator (>=)

This operator checks if the left operand is greater than or equal to the right operand.

• Syntax:

  operand1 >= operand2
  

• Example:

  #include <iostream>
  
  int main() {
      int a = 5, b = 5;
      bool isGreaterOrEqual = (a >= b); // isGreaterOrEqual is true
      std::cout << "a is greater than or equal to b: " << std::boolalpha << isGreaterOrEqual << std::endl;
      return 0;
  }
  

6. Less than or Equal to Operator (<=)

This operator checks if the left operand is less than or equal to the right operand.

• Syntax:

  operand1 <= operand2
  

• Example:

  #include <iostream>
  
  int main() {
      int a = 5, b = 7;
      bool isLessOrEqual = (a <= b); // isLessOrEqual is true
      std::cout << "a is less than or equal to b: " << std::boolalpha << isLessOrEqual << std::endl;
      return 0;
  }
  

Usage of Relational Operators

Relational operators are typically used in conditional statements (like if, while, and for) to control the flow of the program based on comparisons.

Example: Using Relational Operators in Conditional Statements

Here’s an example that uses relational operators to determine if a number is within a specific range.

#include <iostream>

int main() {
    int number;
    std::cout << "Enter a number: ";
    std::cin >> number;

    if (number >= 10 && number <= 20) {
        std::cout << "The number is between 10 and 20." << std::endl;
    } else {
        std::cout << "The number is outside the range." << std::endl;
    }

    return 0;
}

Important Notes

1. Data Types: Relational operators can be used with various data types, including integers, floating-point numbers, and characters.
2. Boolean Results: The result of a relational operation is always a boolean value (true or false).
3. Operator Precedence: Relational operators have lower precedence than arithmetic operators. This means arithmetic operations are evaluated first unless parentheses are used.