C facts & stats

Question 1

In a C program, which function is where execution begins?

Accepted Answer

main(). Every hosted C program starts running in main, which returns an int status to the operating system.

Question 2

Which function from stdio.h is commonly used to print formatted text in C?

Accepted Answer

printf. Its name is short for 'print formatted', and it writes text to standard output.

Question 3

Where was the C language created in the early 1970s?

Accepted Answer

Bell Labs. Dennis Ritchie developed C there, and it was soon used to rewrite the Unix operating system.

Question 4

What does a pointer variable in C store?

Accepted Answer

A memory address. A pointer holds the location of another value, which you reach by dereferencing it.

Question 5

In C, what marks the end of a string stored in a char array?

Accepted Answer

A null character '\0'. C strings have no stored length, so a terminating zero byte marks the end and a 5-letter word needs 6 bytes.

Question 6

C was developed as a successor to which earlier language?

Accepted Answer

B. C grew out of a simpler, typeless language used on early Unix systems, adding data types and more.

Question 7

Which pair of standard library functions allocates and releases heap memory in C?

Accepted Answer

malloc and free. One requests a block of memory at runtime and the other returns it; forgetting to release memory causes leaks.

The basics