20 C Language Question – Answer with Free Notes

1 – Question : What is is C Language ???

C Language is high level Language. It is both general purpose and specific purpose programming language. It is developed to be small and also powerful programming language. Now-a-days C Language has become common programming language for every Application Developer. It was developed at Bell Telephone Laboratory, USA (Now AT and T) in 1972. It is outcome of the efforts of Dennis Ritchie and Brian Kernighan. C is derived from two early Programming Languages such as BCPL (basic Combined Programming Language) and B Language.

2 – Question : Characteristic of C Language

C has Become a popular programming language because of its many features. The Important characteristics of C are:

• C is a general purpose programming language
• C is structured programming language.
• It has rich set of Operators.
• It provides a rich compact representation for expression.
• Supports a Rich set of Data Types.
• Pointer Arithmetic and Pointer Manipulation.

3 – Question : Character Set of C Language

Every Programming Language has its own set of characters to form the lexical elements. The characters used in C are grouped into the following three categories.

1. Alphabets
2. Digits
3. Special Characters

Complete Character Set and Tokens in C

4 – Question : What are Token in C Language ???

The basic and smallest units of a C Language are called C Tokens. There are six types of Token in C.

1. Keywords
2. Identifiers
3. Constant
4. Strings
5. Operators
6. Special Symbols

5 – Question : What are Keywords ???

Every word in a C program is either a keyword or an identifier. All keywords (all reserved words) are basically the sequence of characters that have one or more fixed meanings. And these meanings, in any circumstances, cannot be changed. All C keywords must be written in lowercase letters. Because, In C both uppercase and lowercase letters are significant.

6 – Question : What are Identifiers ???

Identifiers are names given to the program elements such as variables, arrays, and functions. Basically identifiers are the sequence of alphabets and digits.

7 – Question : Rules for Forming Identifier Name…

1. The first character must be an alphabet (uppercase or lowercase) or an underscore.
2. All succeeding characters must be either letters or digits.
3. Uppercase and Lower case Identifiers are different in C.
4. No special character or punctuation symbols are allowed except the underscore “_”.
5. No two successive underscore are allowed.
6. Keywords should not be used as identifiers.

8 – Question : What are C Operators ???

C Language has rich set of Operators. They may operate on a single operand or two operands. They are used to perform basic arithmetic operations, comparison, manipulation of bits and so on.

Complete Topics of Operators in C

9 – Question : What are Arithmetic Operators ???

Arithmetic Operators are used to perform the basic arithmetic operations such as addition, subtraction, multiplication, and division. C Language does not provide an exclusive exponential operator. This can be performed by pow(), which is a library function.

10 – Question : What are Arithmetic Expressions ???

Arithmetic Expressions involving arithmetic operators is called an Arithmetic Expression. It takes one or more operands and connects them by an arithmetic operator. These operands are either integer of floating point numbers.

11 – Question : What are Increments Operators ???

This Operators is used to increment the value of an integer quantity by one. This is represented by “++” (double plus) symbol. This symbol can be placed before or after the integer variable.

12 – Question : What are Decrements Operators ???

This Operators is used to reduce the value of an integer quantity by one. This is represented nu “–” (double minus) symbol. This symbol can be placed either before or after an ineteger variable.

13 – Question : What are Relational Operators ???

These are used for compare two operands. They define the relationship existing between two constants or variables. They result either a TRUE or FALSE value. The value of TRUE is nonzero (i.e., 1) and the value of FALSE is zero.

14 – Question : List of Special Operators in C.

C provides the special Operators in,

1. Comma Operator
2. Size of ()
3. Address Operator
4. Dereferencing Operator
5. Dot Operator
6. Arrow Operator

Complete Data Types in C

15 – Question : What is Data Type Conversion???

In some applications, we may often want to change the data type of the variables. When we declare some variables as int, the desired output may be float or vice-versa. In such situations, we change the nature of the data stored in the variable. This process is known as Data Type Conversion.

16 – Question : What Header Files???

Files that are Placed at the header portion (before main()) of a C Program are called the header files. Normally the standard header file have .h as extension which designates a header file. However, the user-defined header file may have different extensions.

17 – Question : What are Preprocessor Directives ???

C Preprocessor is a collection of special statements called the Preprocessor Directives. The Preprocessor Directives are executed before the C Program is compiled. The C preprocessor directives are useful in performing the following actions:

1. Substitution of values
2. Including files and
3. Conditional Compilations

18 – Question : How many Bitwise Operators are supported by C?

C Supports 6 Bitwise Operators,

1. Bitwise AND
2. Bitwise OR
3. Bitwise XOR
4. Bitwise Complement
5. Bitwise Left Shift
6. Bitwise Right Shift

19 – Question : What is Comma Operator???

The Comma Operator is basically associated with for Statement. It is used for link two or more related expressions together.

20 – Question : What is sizeof() Operator???

The sizeof() operator returns the size (i.e. the number of bytes) of the operand. It should be written in lowercase letters. It must precede its operand. The operand may be a constant, a variable or a data type. It is normally used to determine the size of arrays and structures. It is also used for dynamic memory allocation.