Mastering C++: From Fundamentals to Advanced Programming

Chapter 3: Control Flow and Operators in C++

🔹 1. Introduction

Controlling the flow of execution is fundamental in every programming language. In C++, control flow enables you to make decisions and perform repetitive tasks using:

• Conditional statements (e.g. if, else, switch)
• Loops (e.g. for, while, do-while)
• Operators (arithmetic, comparison, logical, assignment)

This chapter will teach you how to build logic, branch behavior, and repeat actions, all of which are essential for writing functional programs.

🔹 2. C++ Operators

Operators are symbols that perform operations on variables and values.

✅ Arithmetic Operators

✅ Assignment Operators

✅ Comparison Operators

✅ Logical Operators

🔹 3. Conditional Statements

✅ if...else Structure

int age = 20;

if (age >= 18) {

    cout << "Adult";

} else {

    cout << "Minor";

}

✅ if...else if...else

int marks = 85;

if (marks >= 90) {

    cout << "Grade A";

} else if (marks >= 75) {

    cout << "Grade B";

} else {

    cout << "Grade C";

}

✅ switch Statement

int day = 3;

switch(day) {

    case 1: cout << "Monday"; break;

    case 2: cout << "Tuesday"; break;

    case 3: cout << "Wednesday"; break;

    default: cout << "Invalid";

}

🔹 4. Looping in C++

Loops are used to run the same block of code multiple times.

✅ for Loop

for (int i = 1; i <= 5; i++) {

    cout << i << " ";

}

Output: 1 2 3 4 5

✅ while Loop

int i = 1;

while (i <= 5) {

    cout << i << " ";

    i++;

}

✅ do...while Loop

int i = 1;

do {

    cout << i << " ";

    i++;

} while (i <= 5);

✅ The do...while loop always executes at least once.

🔹 5. Loop Control Statements

🔹 6. Flowchart: Loop Example

Start

|

|-- i = 1

|-- While i <= 5

|     Print i

|     i++

|

End

✅ Control flow diagrams are useful for visualizing loop logic in technical interviews.

🔹 7. Nested Loops Example

for (int i = 1; i <= 3; i++) {

    for (int j = 1; j <= i; j++) {

        cout << "* ";

    }

    cout << endl;

}

Output:

*

* *

* * *