Operators in C
Operators in C
One of the most important features of C is that it has a very rich set of built in operators including arithmetic, relational, logical, and bitwise operators.
An operator can be any symbol like + - * / that specifies what operation need to be performed on the data.
For ex: + indicates addition operation* indicates multiplication operation
An operand can be a constant or a variable.
An expression is combination of operands and operators that reduces to a single value.
For ex: Consider the following expression a + b here a and b are operands, while + is an operator.
Types of C operators
C language offers many types of operators.
- Arithmetic operators.
- Assignment operators.
- Relational operators.
- Logical operators.
- Bit wise operators.
- Conditional operators (ternary operators).
- Increment/decrement operators.
- Special operators.
Arithmetic Operators
An arithmetic operator performs mathematical operations such as addition, subtraction and multiplication on numerical values (constants and variables).
| Operator | Description |
| + | Addition |
| - | Subtraction |
| * | Multiplication |
| / | Division |
| % | Modulus (Remainder ) |
Assignment Operators in C
An assignment operator is used for assigning a value to a variable. The most common assignment operator is =
It assign the value from right to left side variable.
| Operator | Description | Explanation |
| = | Simple Equal | C = A + B will assign the value of A + B to C |
| += | Add & assignment | C += A is equivalent to C = C + A |
| -= | Subtract & assignment | C -= A is equivalent to C = C - A |
| *= | Multiply & assignment | C *= A is equivalent to C = C * A |
| /= | Divide & assignment | C /= A is equivalent to C = C / A |
| %= | Modulus & assignment | C %= A is equivalent to C = C % A |
Relational Operators in C
A relational operator checks the relationship between two operands. If the relation is true, it returns 1; if the relation is false, it returns value 0.
Relational operators are used in decision making and loops.
| Operator | Description |
| > | greater than |
| < | less than |
| >= | greater than or equal to |
| <= | less than or equal to |
| == | equal to |
| != | not equal to |
Logical Operators in C
Logical operators are used to combine two or more condition for building complex expression.
| Operator | Operator Name | Description |
| && | AND | Logical AND. True only if all operands are true |
| || | OR | Logical OR. True only if either one operand is true |
| ! | NOT | Logical NOT. True only if the operand is 0 |
Increment and Decrement Operators in C
Increment operators are used to increase the value of the variable by one and decrement operators are used to decrease the value of the variable by one in C programs.
Type of Increment Operator
- Pre increment/decrement Operator (++a, --a)
- Post increment/decrement Operator (a++, a--)
Conditional Operator in C
The conditional operator (? :) is a ternary operator. This operator needs 3 operands to perform the operation.
Syntax:
Variable = <test expression> ? <expression 1> : <expression 2>
Or
<test expression> ? <expression 1> : <expression 2>
The conditional operator works as follows:
Test Expression is Condition
Expression 1 is Statement Followed if Condition is True
Expression 2 is Statement Followed if Condition is False
Example 1:
int num1=10,num2=20,max;
max=(num1>num2)?num1:num2; printf("Max is %d",max);
The output is:
max is 20
Example 2:
int num=45;
(num%2==0)?printf("Number is Even"):printf("Number is Odd");
The Output is:
Number is Odd
Question :What are the alphabets or character set of C programming language?
Answer :
The characters that can be used to form words, numbers and expressions. The characters in C are grouped into the following categories
Letters: Lowercase letters a,b,...,z and uppercase letters A,B,...,Z
Digits: from 0 to 9
White spaces: Space, tab(\t), newline(\n), carriage return(\r), etc
Symbols:
Question : What are C-Tokens? List and define different C-Tokens with examples.
Answer :
A C-Token is a smallest element of a C program. One or more characters are grouped in sequence to form meaningful words. These meaningful words are called C-Tokens. The tokens are broadly classified as follows
Keywords: Keywords are tokens which are used for their intended purpose only. Each keyword has fixed meaning or predefined meaning and that cannot be changed by user. Hence, they are also called as reserved-words.
ex: if, for, while, int, float, break, char ..etc.
Identifiers: As the name indicates, identifier is used to identify various elements of program such as variables, constants, functions, arrays etc.
ex: sum, length, etc.
Constants: A constant is an identifier whose value remains fixed throughout the execution of the program. The constants cannot be modified in the program.
ex: 10, 10.5, 'a', "sri", etc.
Operators: An operator can be any symbol like + - * / that specifies what operation need to be performed on the data.
For ex: + indicates addition operation * indicates multiplication operation / indicates division operation, etc.
Special symbols: The symbols that are used to indicate array subscript, function call, block, etc.
ex: [], (), {}, etc.
Question : What are identifiers? What are the rules for naming a identifier? Give examples.
Answer :
Identifier is used to name various elements of program such as variables, constants,
functions, arrays, functions etc. An identifier is a word consisting of sequence of Letters,
Digits or _(underscore).
Rules to Name identifiers are
1. The variables must always begin with a letter or underscore as the first character.
2. The following letters can be any number of letters, digits or underscore.
3. Maximum length of any identifier is 31 characters for external names or 63 characters
for local names.
4. Identifiers are case sensitive. Ex. Rate and RaTe are two different identifiers.
5. The variable name should not be a keyword.
6. No special symbols are allowed except underscore.
Examples:
Valid identifiers:
Sum
roll_no
_name
sum_of_digits
avg_of_3_nums
Invalid Identifiers and reason for invalid:
$roll_no - Name doesn‟t begin with either letter or underscore
for - keyword is used as name
sum,1 - special symbol comma is not allowed
3_factorial - name begins with digit as first letter
Question : What are constants? List and explain different types of constants with examples
Answer:
A constant is an identifier whose value remains fixed throughout the execution of the
program. The constants cannot be modified in the program.
For example: 1, 3.14512, „z‟, “hello"
Different types of constants are:
1) Integer Constant: An integer is a whole number without any fraction part.
There are 3 types of integer constants:
i) Decimal constants (0 1 2 3 4 5 6 7 8 9) For ex: 0, -9, 22
ii) Octal constants (0 1 2 3 4 5 6 7) For ex: 021, 077, 033
iii) Hexadecimal constants (0 1 2 3 4 5 6 7 8 9 A B C D E F)
For ex: 0x7f, 0x2a, 0x521
2) Floating Point Constant: The floating point constant is a real number.
The floating point constants can be represented using 2 forms:
i) Fractional Form: A floating point number represented using fractional form has an integer part followed by a dot and a fractional part.
For ex: 0.5, -0.99
ii) Scientific Notation (Exponent Form): The floating point number represented using scientific notation has three parts namely: mantissa, E and exponent.
For ex: 9.86E3 imply 9.86 x 103
Programs
Write a program to input number of days from user and display it, week and days format.
For Example
input is : 20 days
then output is:
2 week and 6 days.
Write a program to input number of days from user and display it, Month, Week and Days format. (consider 30days = 1 month)
For Example:
input is : 50 days
output is: 1 month, 2 week and 6 days.
Write a C program which accept a character from user and ASCII Value of that character
Write a C Program to input any number and Check number is Odd or Even Using the Ternary Operator