Python Chapter 3

⚙️ What are Control Statements?

Control statements are used to control the flow of a program — they decide which part of the code will run and how many times.

There are 3 main types:

1. Conditional Statements (Decision making)
2. Looping Statements (Repetition)
3. Jump Statements (Breaking or skipping code)

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🧠 1. Conditional Statements (Decision Making)

These allow the program to make decisions based on conditions.

🔹 if Statement

Runs code only if the condition is true.

if a > b:
    print("a is greater")

🔹 if–else Statement

Runs one block if condition is true, another if false.

if a > b:
    print("a is greater")
else:
    print("b is greater")

🔹 if–elif–else Statement

Used when you have multiple conditions.

if marks >= 90:
    print("Grade A")
elif marks >= 75:
    print("Grade B")
else:
    print("Grade C")

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🔁 2. Looping Statements (Repetition)

Used to repeat a block of code multiple times.

🔹 for Loop

Used when you know how many times to repeat.

for i in range(5):
    print(i)

👉 range(5) means 0 to 4.

🔹 while Loop

Used when you don’t know how many times to repeat.

i = 1
while i <= 5:
    print(i)
    i += 1

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⏭️ 3. Jump Statements

Used to control the flow inside loops.

Statement	Use
break	Exits the loop completely
continue	Skips the current iteration and goes to the next one
pass	Does nothing (used as a placeholder)

Examples:

for i in range(5):
    if i == 3:
        break   # loop stops when i=3
    print(i)

for i in range(5):
    if i == 2:
        continue  # skips when i=2
    print(i)

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💡 4. Nested Statements

You can use one statement inside another.

if a > 0:
    if a % 2 == 0:
        print("Positive and Even")

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