Top C Interview Questions and Answers | C Programming Language Questions
Tejasvee Sharma
Jan 02, 2022
If you are preparing for a C language job interview then this page will be very useful to you. Here we have provided top C interview questions to prepare. In the below section we have covered basic, intermediate, advanced, and coding C interview questions and answers for your practice. So, prepare from the given C programming language interview questions and clear your job interview.
About C: C Programming language is a general-purpose, technical computer programming language that supports lexical variable scope, structured programming, and recursion, with a static type system.
C is a mid-level and technical programming language. The technical programming language is also called the structured programming language is a method in which large coding is split down into shorter modules, and each module uses a structured program. This method reduces errors and misinterpretations.
2. Explain Dangling Pointer Variable in C Programming?
A Pointer in C language is used to point to the memory zone of a current variable. In case if that specific variable is eliminated and the Pointer is still pointing to the exact memory zone, then that specific pointer variable is known as Dangling Pointer Variable.
3. Explain the Scope of the variable in C language?
It can be described as the section of the code area where the variables are declared and directly accessed in the program. In C, all identifiers are statically scoped.
4. Explain static variables and functions?
They are declared using the static keyword are known as Static Variable and Static Functions. The Static Variable and Static Functions have their scope limited to the function in which they are declared.
5. What is the difference between calloc() and malloc()?
The difference between calloc() and malloc() is that calloc() will load all the allocated memory locations with value 0 whereas malloc() will not.
6. Tell the valid places where the developer can apply Break Control Statement?
Break Control statement is valid in a loop and Switch control statements.
7. How do we reserve a negative integer?
To reserve a negative integer, we require to follow these steps. Compute the two’s complement of the similar positive integer.
Eg: 1011 (-5)
Step-1: One’s complement of 5: 1010
Step-2: Add 1 to above, giving 1011, which is -5
8. Tell the difference between Formal Parameters and Actual Parameters.
The Parameters which are transmitted from the primary function to the subdivided function are known as Actual Parameters and the parameters declared at the Subdivided function end are known as Formal Parameters.
9. Can a C program be executed in the lack of a main()?
The C program can easily be compiled but will not be executed. To run any C program, the main() function is needed.
10. Explain Nested Structure?
When a data member of a single structure is guided by the data member of another function then it is said Nested Structure.
11. Explain C Token?
Keywords, Special Symbols, Constants, Strings, Identifiers, Operators, used in the C program are denoted as C Tokens.
12. Explain Preprocessor?
A Preprocessor Directive is evaluated as a built-in predefined function or macro that serves as a directive to the compiler and gets implemented before the actual C Program is enforced.
13. Why C is named the Mother of all Languages?
C languages presented numerous core concepts and data structures such as strings, arrays, functions, lists, etc. Many languages developed after C are created based on C Language. Hence, it is viewed as the mother of all languages.
14. What is the objective of printf() and scanf() in C Programming?
printf() is used to publish the values on the screen. Whereas scanf() is used to examine the values. We require a suitable datatype format specifier for both printing and scanning purposes. For example,
%c: It is a datatype format specifier used to show and scan a character value.
%d: It is a datatype format specifier used to print and scan an integer value.
%f: It is a datatype format specifier used to show and scan a float value.
%s: It is a datatype format specifier used to print and scan a string.
15. Explain array?
The array is a straightforward data structure that reserves numerous elements of a similar datatype in a reserved and sequential way. Some types of arrays are:
One Dimensional Array
Two Dimensional Array
Multi-Dimensional Array
16. Explain /0 character?
The given /0 Symbol is known as Null Character. It is viewed as the terminating character utilized in strings to declare the end of the string to the compiler.
17. Differentiate between the Compiler and the Interpreter?
A compiler is utilized in C Language and it decrypts the whole program into the Machine Code in one go. An interpreter is used in Java Programming Langauge and different high-end programming languages. It is created to gather code in a line-by-line fashion.
18. Can I use int datatype to reserve 32768 value?
No, the Integer datatype will work within the range between -32768 and 32767. Any value surpassing that will not be reserved. We can use either float or long int.
19. Show the function to declare in C Language?
A function in C language is declared as follows,
return_type function_name(formal parameter list)
{
Function_Body;
}
20. Where can we not use &(address operator in C)?
We can’t use & on constants and a variable that is declared operating the register storage class.
21. Show an example of a structure in C Language
Structure is described as a user-defined data type that is created to store various data members of the various data types as one unit. A structure will consume the memory equivalent to the summation of all the data members.
struct employee
{
char name[10];
int age;
}e1;
int main()
{
printf("Enter the name");
scanf("%s",e1.name);
printf("n");
printf("Enter the age");
scanf("%d",&e1.age);
printf("n");
printf("Name and age of the employee: %s,%d",e1.name,e1.age);
return 0;
}
22. What is the difference between getch() and getche().
Both the functions are created to read characters from the keyboard and the difference is that:
etch(): reads characters from the keyboard but it don't use any buffers. Hence, data is not shown on the screen.
getche(): reads characters from the keyboard and it utilizes buffer. Hence, data is shown on the screen.
//Example
#include<stdio.h>
#include<conio.h>
int main()
{
char ch;
printf("Please enter a character ");
ch=getch();
printf("nYour entered character is %c",ch);
printf("nPlease enter another character ");
ch=getche();
printf("nYour new character is %c",ch);
return 0;
}
//Output
Please enter a character
Your entered character is x
Please enter another character z
Your new character is z
23. What is toupper() with example?
toupper() is a function created to transform lowercase words/characters into upper case.
//Example
#include<stdio.h>
#include<ctype.h>
int main()
{
char c;
c=a;
printf("%c after conversions %c", c, toupper(c));
c=B;
printf("%c after conversions %c", c, toupper(c));
//Output:
a after conversions A
B after conversions B
