Basic C Programming - Control Flow

What is the syntax for an if statement in C?

• if (condition) then // code block

• if (condition) { // code block

• if (condition) { // code block }

• if (condition) then { // code block }

How do you write an if else statement in C?

• if (condition) { // code to be executed if the condition is true } else { // code to be executed if the condition is false }

• if (condition) { // code to be executed if the condition is true } else { // code to be executed if the condition is false }

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

• if (condition) { // code to be executed if the condition is false } else { // code to be executed if the condition is true }

Explain the concept of nested if else in C with an example.

• In nested if else, the else block must always come before the if block

• Example: #include int main() { int num = 10; if(num > 0) { if(num % 2 == 0) { printf("%d is a positive even number.", num); } else { printf("%d is a positive odd number.", num); } } else { printf("%d is not a positive number.", num); } return 0; }

• Nested if else can only be used with integers in C

• Nested if else is not supported in C

When would you use a switch statement in C?

• When you have multiple conditions to evaluate and different actions to take based on each condition.

• When you want to execute a single action based on a condition

• When you need to loop through a collection of elements

• When you want to handle exceptions in your code

What is the purpose of the default case in a switch statement?

• To handle situations where none of the specified cases match the input value.

• To provide an alternative case for the input value

• To terminate the switch statement immediately

• To skip the switch statement and move to the next block of code

Write a C program to check if a number is positive, negative, or zero using if else.

• Here is a sample C program: #include int main() { int num; printf("Enter a number: "); scanf("%d", &num); if(num > 0) printf("%d is positive.", num); else if(num < 0) printf("%d is negative.", num); else printf("%d is zero.", num); return 0; }

• printf("%d is non-negative.", num);

• if(num >= 0)

• int num = 0;

How can you use nested if else to determine the largest of three numbers in C?

• if (num1 >= num2) { if (num1 >= num3) { largest = num1; } else { largest = num3; } } else { if (num2 >= num3) { largest = num2; } else { largest = num3; } }

• if (num1 >= num2) { largest = num1; } else { largest = num2; }

• if (num1 >= num2 && num1 >= num3) { largest = num1; }

• if (num1 >= num2) { largest = num1; } else if (num2 >= num3) { largest = num2; } else { largest = num3; }

Give an example of a switch statement to display the day of the week based on user input.

• switch (userInput) { case 1: console.log('Monday'); break; case 2: console.log('Tuesday'); break; case 3: console.log('Wednesday'); break; case 4: console.log('Thursday'); break; case 5: console.log('Friday'); break; case 6: console.log('Saturday'); break; case 7: console.log('Sunday'); break; default: console.log('Invalid input'); }

• if (userInput === 1) { console.log('Monday'); } else if (userInput === 2) { console.log('Tuesday'); } else if (userInput === 3) { console.log('Wednesday'); } else if (userInput === 4) { console.log('Thursday'); } else if (userInput === 5) { console.log('Friday'); } else if (userInput === 6) { console.log('Saturday'); } else if (userInput === 7) { console.log('Sunday'); } else { console.log('Invalid input'); }

• for (let i = 1; i <= 7; i++) { if (userInput === i) { console.log(['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'][i - 1]); break; } }

• switch (userInput) { case 1: console.log('Monday'); break; case 2: console.log('Tuesday'); break; case 3: console.log('Wednesday'); break; case 4: console.log('Thursday'); break; case 5: console.log('Friday'); break; case 6: console.log('Saturday'); break; case 7: console.log('Sunday'); break; default: console.log('Invalid input'); }

Explain the difference between if else and switch statements in C.

• The if else statement is more flexible and can handle complex conditions, whereas the switch statement is more concise and efficient for multiple branches.

• The if else statement is more efficient than the switch statement.

• The switch statement can handle more complex conditions than the if else statement.

• Both if else and switch statements are interchangeable in C.

When should you avoid using nested if else statements in C?

• When the code becomes hard to read, maintain, or debug.

• When the code has few conditions to check

• When the code is easy to read and maintain

• When the code is simple and straightforward