Decision Making

1. The if Statement

The simplest form of decision-making. It executes a block of code only if the condition is true.

int age = 20;
if (age >= 18) {
    printf("You are eligible to vote.");
}

2. The if...else Statement

Provides an alternative path. If the condition is false, the else block runs.

int marks = 75;
if (marks >= 35) {
    printf("Result: Pass\n");
} else {
    printf("Result: Fail\n");
}

3. The Nested if Statement

An if inside another if. Used when multiple conditions must be met in sequence.

int x = 10, y = 20;
if (x == 10) {
    if (y == 20) {
        printf("Both conditions are true\n");
    }
}

4. The Nested if...else (Else-If Ladder)

Used to check multiple distinct possibilities in a sequence.

int score = 85;
if (score >= 90) {
    printf("Grade: A\n");
} else if (score >= 80) {
    printf("Grade: B\n");
} else {
    printf("Grade: C\n");
}

5. The switch Statement

A cleaner way to handle multiple fixed values for a single variable.

int day = 2;
switch (day) {
    case 1: 
        printf("Monday"); 
        break;
    case 2: 
        printf("Tuesday"); 
        break;
    default: 
        printf("Other day");
}