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Interview :: C

1) What is C language?

C is a mid-level and procedural programming language. The Procedural programming language is also known as the structured programming language is a technique in which large programs are broken down into smaller modules, and each module uses structured code. This technique minimizes error and misinterpretation.

2) Why is C known as a mother language?

C is known as a mother language because most of the compilers and JVMs are written in C language. Most of the languages which are developed after C language has borrowed heavily from it like C++, Python, Rust, javascript, etc. It introduces new core concepts like arrays, functions, file handling which are used in these languages.

3) Why is C called a mid-level programming language?

C is called a mid-level programming language because it binds the low level and high -level programming language. We can use C language as a System programming to develop the operating system as well as an Application programming to generate menu driven customer driven billing system.

4) Who is the founder of C language?

Dennis Ritchie.

5) When was C language developed?

C language was developed in 1972 at bell laboratories of AT&T.

6) What are the features of the C language?

The main features of C language are given below:

  • Simple: C is a simple language because it follows the structured approach, i.e., a program is broken into parts
  • Portable: C is highly portable means that once the program is written can be run on any machine with little or no modifications.
  • Mid Level: C is a mid-level programming language as it combines the low- level language with the features of the high-level language.
  • Structured: C is a structured language as the C program is broken into parts.
  • Fast Speed: C language is very fast as it uses a powerful set of data types and operators.
  • Memory Management: C provides an inbuilt memory function that saves the memory and improves the efficiency of our program.
  • Extensible: C is an extensible language as it can adopt new features in the future.
7) What is the use of printf() and scanf() functions?

printf(): The printf() function is used to print the integer, character, float and string values on to the screen.

Following are the format specifier:

  • %d: It is a format specifier used to print an integer value.
  • %s: It is a format specifier used to print a string.
  • %c: It is a format specifier used to display a character value.
  • %f: It is a format specifier used to display a floating point value.

scanf(): The scanf() function is used to take input from the user.

8) What is the difference between the local variable and global variable in C?

Following are the differences between a local variable and global variable:

Basis for comparison Local variable Global variable
Declaration A variable which is declared inside function or block is known as a local variable. A variable which is declared outside function or block is known as a global variable.
Scope The scope of a variable is available within a function in which they are declared. The scope of a variable is available throughout the program.
Access Variables can be accessed only by those statements inside a function in which they are declared. Any statement in the entire program can access variables.
Life Life of a variable is created when the function block is entered and destroyed on its exit. Life of a variable exists until the program is executing.
Storage Variables are stored in a stack unless specified. The compiler decides the storage location of a variable.
9) What is the use of a static variable in C?

Following are the uses of a static variable:

  • A variable which is declared as static is known as a static variable. The static variable retains its value between multiple function calls.
  • Static variables are used because the scope of the static variable is available in the entire program. So, we can access a static variable anywhere in the program.
  • The static variable is initially initialized to zero. If we update the value of a variable, then the updated value is assigned.
  • The static variable is used as a common value which is shared by all the methods.
  • The static variable is initialized only once in the memory heap to reduce the memory usage.
10) What is the use of the function in C?

Uses of C function are:

  • C functions are used to avoid the rewriting the same code again and again in our program.
  • C functions can be called any number of times from any place of our program.
  • When a program is divided into functions, then any part of our program can easily be tracked.
  • C functions provide the reusability concept, i.e., it breaks the big task into smaller tasks so that it makes the C program more understandable.