Day 8 Programming Video Tutorial: Mastering Loops and Conditional Statements316

Welcome back to our programming video tutorial series! Today, we're diving into the heart of almost any program: loops and conditional statements. These fundamental building blocks allow your programs to make decisions and repeat actions, enabling complex logic and functionality. By the end of this tutorial, you'll be confidently using `for` and `while` loops, and `if`, `else if`, and `else` statements to control the flow of your code. We'll cover this in a practical, hands-on way, building on what you've learned in previous days.

Let's start with loops. Loops are crucial for automating repetitive tasks. Imagine you need to print the numbers from 1 to 10. Writing ten separate `print()` statements would be inefficient and tedious. Loops elegantly solve this problem. We primarily use two types: `for` loops and `while` loops.

`for` loops are ideal when you know the number of iterations in advance. They're perfect for iterating over a sequence (like a list or string) or a range of numbers. Here's the basic syntax (using Python as our example language, but the concepts are transferable to other languages):```python
for i in range(1, 11): # Iterates from 1 to 10 (inclusive of 1, exclusive of 11)
print(i)
```

This code will print the numbers 1 through 10, one per line. The `range()` function generates a sequence of numbers. You can adjust the start, stop, and step values to control the iteration. For example, `range(2, 20, 2)` would generate even numbers from 2 to 18.

You can also iterate directly over sequences:```python
my_list = ["apple", "banana", "cherry"]
for fruit in my_list:
print(fruit)
```

This will print each item in `my_list` on a new line.

`while` loops, on the other hand, continue as long as a specified condition is true. This is useful when you don't know the exact number of iterations beforehand. Here's the syntax:```python
count = 0
while count < 5:
print(count)
count += 1
```

This code will print numbers 0 through 4. The loop continues until `count` becomes 5, at which point the condition `count < 5` becomes false.

It's crucial to be mindful of infinite loops. If your `while` loop's condition never becomes false, the program will run indefinitely. Always ensure your loop has a mechanism to terminate.

Now, let's move on to conditional statements. These allow your program to make decisions based on different conditions. The most common is the `if` statement:```python
age = 20
if age >= 18:
print("You are an adult.")
```

This code will print "You are an adult." only if the `age` variable is greater than or equal to 18.

You can extend this with `else if` (elif in Python) and `else` to handle multiple conditions:```python
age = 15
if age >= 18:
print("You are an adult.")
elif age >= 13:
print("You are a teenager.")
else:
print("You are a child.")
```

This code will categorize the `age` into one of three categories based on its value. The conditions are checked sequentially; the first condition that evaluates to true will be executed, and the rest will be skipped.

Nested loops and conditional statements are also very common. You can place loops inside other loops or conditional statements inside loops (and vice-versa) to create complex logic. For instance, you might use nested loops to iterate through a two-dimensional array or a nested conditional statement to handle multiple scenarios within a decision-making process.

Practical Application: Let's create a small program that uses both loops and conditional statements. We'll write a program that checks if a number is prime. A prime number is a natural number greater than 1 that is not a product of two smaller natural numbers. ```python
num = 17
is_prime = True
if num

2025-04-18

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