Lecture 6
- 1. C++ Programming Logical Opperators, Pointers and arrays Mohammed Jehan Lecturer
- 2. Logical Operators Use logical operators to combine conditional statements and return true or false. The AND operator works the following way: In the AND operator, both operands must be true for the entire expression to be true.
- 3. The AND Operator For example: int age = 20; if (age > 16 && age < 60) { cout << "Accepted!" << endl; } In the example above, the logical AND operator was used to combine both expressions. The expression in the if statement evaluates to true only if both expressions are true.
- 4. The AND Operator Within a single if statement, logical operators can be used to combine multiple conditions. int age = 20; int grade = 80; if (age > 16 && age < 60 && grade > 50) { cout << "Accepted!" << endl; }
- 5. The OR Operator The OR (||) operator returns true if any one of its operands is true. Example: int age = 16; int score = 90; if (age > 20 || score > 50) { cout << "Accepted!" << endl; } You can combine any number of logical OR statements you want. In addition, multiple OR and AND statements may be chained together.
- 6. Logical NOT The logical NOT (!) operator works with just a single operand, reversing its logical state. Thus, if a condition is true, the NOT operator makes it false, and vice versa. int age = 10; if ( !(age > 16) ) { cout << "Your age is less than 16" << endl; } // Outputs "Your age is less than 16" Be careful using this, because !false means true.
- 7. while vs. do...while Try the following example to understand all the logical operators #include <iostream> using namespace std; main() { int a = 5; int b = 20; int c ; if(a && b) { cout << "Line 1 - Condition is true"<< endl ; } if(a || b) { cout << "Line 2 - Condition is true"<< endl ; } /* Let's change the values of a and b */ a = 0; b = 10; if(a && b) { cout << "Line 3 - Condition is true"<< endl ; } else { cout << "Line 4 - Condition is not true"<< endl ; } if(!(a && b)) { cout << "Line 5 - Condition is true"<< endl ; } return 0;