Self-Taught Programming: Mastering Loops and Control Flow (Lesson 4)243

Welcome back, aspiring programmers! In our previous lessons, we covered the fundamentals of variables, data types, and basic input/output operations. Now, it's time to delve into the heart of programming: loops and control flow. These concepts are crucial for creating dynamic and responsive programs that can handle various situations and perform repetitive tasks efficiently. This fourth lesson will equip you with the tools to write more sophisticated and powerful code.

Let's start by understanding what control flow is. Essentially, it's the order in which your program executes instructions. Without control flow, your program would simply run line by line from top to bottom, a very limited approach. Control flow statements allow you to alter this execution sequence, enabling you to make decisions, repeat actions, and handle different scenarios based on conditions.

The primary control flow tools are:
Conditional Statements (if, else if, else): These allow you to execute different blocks of code based on whether a certain condition is true or false. The basic structure is as follows:


if (condition) {
// Code to execute if the condition is true
} else if (anotherCondition) {
// Code to execute if the first condition is false and this one is true
} else {
// Code to execute if none of the above conditions are true
}

For example, let's say you want to check if a number is positive, negative, or zero:
int number = 10;
if (number > 0) {
("The number is positive.");
} else if (number < 0) {
("The number is negative.");
} else {
("The number is zero.");
}



Loops (for, while, do-while): Loops allow you to repeatedly execute a block of code until a certain condition is met. This is essential for automating repetitive tasks.

The `for` loop is typically used when you know the number of iterations in advance:
for (int i = 0; i < 10; i++) {
("Iteration: " + i);
}

This loop will print "Iteration: " followed by a number from 0 to 9. The loop starts with `i = 0`, continues as long as `i < 10`, and increments `i` by 1 after each iteration.

The `while` loop continues as long as a condition is true:
int count = 0;
while (count < 5) {
("Count: " + count);
count++;
}

This will print "Count: " followed by numbers 0 to 4. The loop continues until `count` becomes 5.

The `do-while` loop is similar to a `while` loop, but it guarantees at least one execution of the loop body:
int count = 0;
do {
("Count: " + count);
count++;
} while (count < 5);

This also prints "Count: " followed by numbers 0 to 4. The key difference is that the condition is checked *after* the loop body is executed once.

Nested Loops: You can place loops inside other loops to create more complex patterns. For example, to print a multiplication table:
for (int i = 1; i

2025-06-19

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