Learning C Language is the first important step that a science student take in the journey of their education. C language comprises of several small programs to even much large programs which can be learn easily. C language has been told as an easy language of learning and the programming concept in the world of computers. Different questions based on C programming are the hot topics and most asked questions that every interviewer asked during the recruitment of any organisation. Lets have a look over C interview questions with answers that has been asked in the various technical interviews-
C Interview questions with answers
1. What is a pointer?
A pointer is a special variable, which stores the memory address. The ‘ampersand’ denoted by ‘&’ and the ‘dereferencing’ factor denoted by ‘*’ are the necessities of pointers. Ampersand in front of a variable gets its address and asterisk in front of a pointer gets its value.
2. What is null pointer?
Null pointer is a pointer which cannot point to anywhere in the program, but uninitialised pointer can point to anywhere in the users program. In C, if the pointer tried to access 0th location, operating system kills the running program because operating system does not allow to access 0th value.
3. Define function pointer?
The function pointer is the pointer which accesses the address of a function. The running program occupies some memory space. Both the executable compiled program code and as well as user variables works on function pointers.
In the C, each function has an address in a code segment.
4. What is volatile variable?
Volatile variables are those variables which alters the default way of the program.
The variable which do not change while compiling but are changeable during execution.
5. Difference between global and static variable?
Static variables persist throughout the scope, but the lifespan is not throughout the program. Global variables persist throughout the scope of base blocks of memory that is their lifespan is throughout the program.
6. What are the files automatically opened when C file is executed?
Standard in, standard out, standard error (stdin, stdout, stderr) are the files which are automatically opened when C file is executed.
7. Compare between array and pointer.
Array can allocate variables but cannot reallocate those variable if required. Whereas the pointer was assigned to allocate variables and they can also relocate and also are resizable.
8. Define function prototype?
The function prototype is the prototype which depends on the following:
a. No. of input types
b. No. of outputs which are to be returned
9. Where the function pointers can be used?
The function pointers can be used when if/switch statements are present,in late binding(variation tables) and to implement call backs activities.
10 What do you mean by #include<stdio.h>?
In C, the hash function # tells the compiler that a statement should be sent to the C preprocessor. The include looks after the new files and replace the contents of those files. and stdio.h will be valid only for the printf, scanf functions.
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