14 CS fundamental questions to prepare for your next interview & not sound like a vibe-coder!

Optimizing Program Performance

1. Is a switch statement always more efficient than a sequence of if-else statements?

2. How much overhead is incurred by a function call?

3. Is a while loop more efficient than a for loop?

4. Are pointer references more efficient than array indexes?

5. Why does our loop run so much faster if we sum into a local variable instead of an argument that is passed by reference?

6. How can a function run faster when we simply rearrange the parentheses in an arithmetic expression?

Understanding link-time errors

1. What does it mean when the linker reports that it cannot resolve a reference?

2. What is the difference between a static variable and a global variable?

3. What happens if you define two global variables in different C files with the same name?

4. What is the difference between a static library and a dynamic library?

5. Why does it matter what order we list libraries on the command line?

6. And scariest of all, why do some linker-related errors not appear until run time?

Avoiding security holes

1. What are buffer overflow vulnerabilities?

2. What is the program stack?