Keywords in C
A keyword is a reserved word. We cannot use it as a variable name, constant name, etc. There are only 32 reserved words (keywords) in the C language.
A list of 32 keywords in the C language is given below :
| auto | break | case | char |
| const | continue | default | do |
| double | else | enum | extern |
| float | for | goto | if |
| int | long | register | return |
| short | signed | sizeof | static |
| struct | switch | typedef | union |
| unsigned | void | volatile | while |
C Operators
An operator is simply a symbol that is used to perform operations. There are the following types of operators to perform different types of operations in C language.
- Arithmetic Operators
- Relational Operators
- Logical Operators
- Bitwise Operators
- Assignment Operator
1. Arithmetic Operators
| Operator | Description |
|---|---|
| + | Addition |
| - | Subtraction |
| * | Multiplication |
| / | Division |
| % | Modulus |
2. Relational Operators
| Operator | Description |
|---|---|
| == | Is equal to |
| != | Is not equal to |
| > | Greater than |
| < | Less than |
| >= | Greater than or equal to |
| <= | Less than or equal to |
3. Logical Operators
| Operator | Description | Example |
|---|---|---|
| && | Logical AND operator. If both the operands are satisfied, then the condition is true. | (A && B) |
| || | Logical OR operator. If any of two operands is true, then condition becomes true. | (A || B) |
| ! | Logical NOT operator. It is used to reverse the logical state of its operand. If condition is true, then logical NOT operator will make it false. | !(A && B) or !(A || B) |
4. Bitwise Operators
| a | b | a & b | a | b | a ^ b |
|---|---|---|---|---|
| 0 | 0 | 0 | 0 | 0 |
| 0 | 1 | 0 | 1 | 1 |
| 1 | 1 | 1 | 1 | 0 |
| 1 | 0 | 0 | 1 | 1 |
- ~ is the binary one's complement operator.
- << is the binary left shift operator.
- >> is the binary right shift operator.
5. Assignment Operators
| Operator | Description |
|---|---|
| = | Simple assignment operator. Assigns values from right side operands to left side operands. |
| += | Add AND assignment operator. It adds the right operand to the left operand and assign the result to the left operand. |
| -= | Subtract AND assignment operator. It subtracts the right operand to the left operand and the result is assigned to the left operand. |
| *= | Multiply AND assignment operator. It multiplies the right operand with the left operand and the result is assigned to the left operand. |
| /= | Divide AND assignment operator. It divides the left operand with the right operand and the result is assigned to the left operand. |
Precedence and Associativity of Operators in C
The precedence of operator specifies that which operator will be evaluated first and next.
The associativity specifies the operator direction to be evaluated; it may be left to right or right to left.
| Category | Operators | Associativity |
|---|---|---|
| Postfix | () [] {} | Left to Right |
| Multiplicative | * / % | Left to Right |
| Additive | + - | Left to Right |
| Shift | << >> | Left to Right |
| Relational | < <= > >= | Left to Right |
| Equality | == != | Left to Right |
| Bitwise AND | & | Left to Right |
| Bitwise XOR | ^ | Left to Right |
| Bitwise OR | | | Left to Right |
| Logical AND | && | Left to Right |
| Logical OR | || | Left to Right |
| Assignment | = += -= *= /= %= >>= <<= &= ^= |= | Right to Left |
The + and - are equal in precedence, as *, /, and %.
The *, /, and % are performed first in order from left to right and then + and -, also in order left to right.
We can change the order of operations by using paranthesis () to indicate which operations are to be performed first.
Comments in C
Comments in C language are used to provide information about lines of code. It is widely used for documenting code. There are 2 types of comments in the C language :
- Single Line Comments
- Multi-Line Comments
1. Single Line Comments
Single line comments are represented by double slash // or \\.
#include <stdio.h>
int main()
{
// printing information
printf("Hello C");
return 0;
}
Output :
Hello C
Even we can place the comment after the statement.
printf("Hello C"); // printing information
2. Multiple Line Comments
Multi-Line comments are represented by slash asterisk /* ..... */. It can occupy many line of code, but it can't be nested.
#include <stdio.h>
int main()
{
/* printing information
Multi-Line Comment */
printf("Hello C");
return 0;
}
Output :
Hello C
Comments
Post a Comment