Decision Making in C

Hey there! In this guide, we'll explore decision-making in C. Decision-making structures allow you to execute different blocks of code based on certain conditions. Let's dive in!

• Decision-making structures allow you to execute different blocks of code based on certain conditions.
• C provides several constructs for decision-making, including if, else, else if, and switch.

1. The if Statement

Syntax:

if (condition) {
    // code to be executed if condition is true
}

Example:

#include <stdio.h>

int main() {
    int num = 10;
    if (num > 0) {
        printf("The number is positive.\n");
    }
    return 0;
}

2. The if...else Statement

Syntax:

if (condition1) {
    // code to be executed if condition1 is true
} else {
    // code to be executed if condition1 is false
}

Example:

#include <stdio.h>

int main() {
    int num = -5;
    if (num > 0) {
        printf("The number is positive.\n");
    } else {
        printf("The number is not positive.\n");
    }
    return 0;
}

3. The if...else if...else Statement

Syntax:

if (condition1) {
    // code to be executed if condition1 is true
} else if (condition2) {
    // code to be executed if condition2 is true
} else {
    // code to be executed if both conditions are false
}

Example:

#include <stdio.h>

int main() {
    int num = 0;
    if (num > 0) {
        printf("The number is positive.\n");
    } else if (num < 0) {
        printf("The number is negative.\n");
    } else {
        printf("The number is zero.\n");
    }
    return 0;
}

4. The switch Statement

Syntax:

switch (expression) {
    case value1:
        // code to be executed if expression == value1
        break;
    case value2:
        // code to be executed if expression == value2
        break;
    default:
        // code to be executed if expression doesn't match any case
}

Example:

#include <stdio.h>

int main() {
    int day = 3;
    switch (day) {
        case 1:
            printf("Monday\n");
            break;
        case 2:
            printf("Tuesday\n");
            break;
        case 3:
            printf("Wednesday\n");
            break;
        default:
            printf("Not a valid day\n");
    }
    return 0;
}

5. Nested if Statements

Example:

#include <stdio.h>

int main() {
    int num = 15;
    if (num > 10) {
        printf("The number is greater than 10.\n");
        if (num > 20) {
            printf("The number is also greater than 20.\n");
        }
    }
    return 0;
}

6. Conditional Operators

C++ also supports conditional operators for compact decision-making.

Ternary Operator

(condition) ? expression1 : expression2;

Example:

#include <stdio.h>

int main() {
    int num = 10;
    const char* result = (num > 0) ? "Positive" : "Non-positive";
    printf("%s\n", result);
    return 0;
}

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Understanding decision-making structures in C is crucial for controlling the flow of your program and executing different actions based on conditions. Happy coding!