C Interview Questions AND ANSWER

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What is C language?
The C programming language is a standardized programming language
developed in the early 1970s by Ken Thompson and Dennis Ritchie for
use on the UNIX operating system. It has since spread to many other
operating systems, and is one of the most widely used programming
languages. C is prized for its efficiency, and is the most popular
programming language for writing system software, though it is also
used for writing applications.


printf() Function
What is the output of printf("%d")?
1. When we write printf("%d",x); this means compiler will print the
value of x. But as here, there is nothing after %d so compiler will show
in output window garbage value



malloc() Function- What is the difference between "calloc(...)" and
"malloc(...)"?
1. calloc(...) allocates a block of memory for an array of elements of a
certain size. By default the block is initialized to 0. The total number of
memory allocated will be (number_of_elements * size).
malloc(...) takes in only a single argument which is the memory
required in bytes. malloc(...) allocated bytes of memory and not blocks
of memory like calloc(...).


Compilation How to reduce a final size of executable?
Size of the final executable can be reduced using dynamic linking for
libraries.


What does static variable mean?

there are 3 main uses for the static.

1. If you declare within a function:
It retains the value between function calls

2.If it is declared for a function name:
By default function is extern..so it will be visible from other files if the
function declaration is as static..it is invisible for the outer files

3. Static for global variables:
By default we can use the global variables from outside files If it is
static global..that variable is limited to with in the file
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