C Programming – Day 3 | Conditional Statements (if, else, else-if, switch) for Beginners

CONDITIONAL STATEMENTS (if, else, else-if, switch) 

DAY - 3

✅ We’ll continue the learning smoothly.

📍 Day-3 — Conditional Statements (if, else, else-if, switch)

Today you will learn:
1️⃣ If statement
2️⃣ If…Else
3️⃣ Else-If Ladder
4️⃣ Nested If
5️⃣ Switch-Case
6️⃣ Mini Project + Quiz

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✅ 1. If Statement

Executes code only if condition is true ✅

int age = 18;
if(age >= 18){
    printf("Adult");
}

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✅ 2. If…Else

int n;
scanf("%d", &n);

if(n % 2 == 0)
    printf("Even");
else
    printf("Odd");

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✅ 3. Else-If Ladder

Used when multiple conditions exist

int marks;
scanf("%d", &marks);

if(marks >= 80)
    printf("A+");
else if(marks >= 70)
    printf("A");
else if(marks >= 60)
    printf("B");
else
    printf("Fail");

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✅ 4. Nested If

int age = 20;
if(age > 0) {
    if(age >= 18)
        printf("Adult");
    else
        printf("Child");
}

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✅ 5. Switch-Case

Used for menu-type choices

int choice;
scanf("%d", &choice);

switch(choice) {
    case 1: printf("Tea"); break;
    case 2: printf("Coffee"); break;
    default: printf("Water");
}

✅ Use break to stop falling into the next case

✅ default = else

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🧪 Practice Example

#include <stdio.h>

int main() {
    int num;
    printf("Enter a number: ");
    scanf("%d", &num);

    if(num > 0)
        printf("Positive");
    else if(num < 0)
        printf("Negative");
    else
        printf("Zero");

    return 0;
}

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✅ Task-3 (You Must Solve)

Write a program:

✔ Input a number
✔ Check:

• If multiple of 3 and 5, print: Divisible by both

• Else if only divisible by 3, print: Divisible by 3

• Else if only divisible by 5, print: Divisible by 5

• Otherwise: Not divisible

📌 Hint: Use % operator
📌 Use if…else-if

Example outputs:

Divisible by both

or

Not divisible

✅ Send me your code — I will correct and add.

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📝 Quick Quiz — Day-3

Reply like: 1B, 2A, 3C

1️⃣ Which statement is used for multi-way menu?
A) if
B) switch
C) else

2️⃣ Condition true → if block executes
A) True
B) False

3️⃣ Which keyword stops falling into next case?
A) else
B) return
C) break

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✅ When you reply with:

✔ Task-3 Code

✔ Quiz Answers

➡ I will mark Day-3 Completed

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Send your Task-3 solution now — I’m ready to check! 😄

✅ NEXT - DAY - 4