Programming in C lecture 3 countiue (Book)

Operators

Assignment operators

(In
C) are use to assign a value to a variable and that operator is “=”. Remember that we can’t put
expressions on left hand side of any assignment operator. X=X+1=X’s old value + 1

Arithmetic operators

(In C) are used for
Arithmetic operations (Remember that
right hand side of = is not effected by the operation) and only the
following operators are use for Arithmetic operations:

                                                                  Purpose
     How to use the operators in C

1)      +                                                  for addition                            X= 1 + 2 = 3

2)      –                                                for subtraction                         Y
= 2 – 1 = 1

3)      /                                                   for dividing                            Z
= 4 / 2 = 2

Note:

Dividing by 0 is illegal and if division is of integers then
fractional part of that division will truncate. All unknowns are variables

4)      *                                              for multiplication                        J = 3 * 6 = 1 8

5)      %                                       for taking the remainder                  I = 5  %  4 =
1

 

Relational operators (In C) are used for any
kind or comparison and only following operator are use:

1)      <                                               shows less than            

2)      >                                            shows greater than

3)      = =                                            shows equal to

4)      !=                                           shows not equal to

5)      <=                                    shows less than or equal to

6)      >=                                  shows greater than or equal to

Not operators (In C) are used for any kind
of ignorance and they are as follow:

1)!True                                               for
showing false                       (!(true
condition here))

2)!False                                               for
showing true                        (!(false
condition here))

Precedence

The brackets are solve first, then *, / and % are
solve, then + and – are solve.

Note:

The
expressions are solve left to right (in C)

 

Keywords

There are certain
keywords like “main ()”and are a followed:

1)   Main ( )                                   4)
While ( )

2)   If ( )                                         5)
Do ( )

3)   Else ( )                                    6)
For( )

Note:

The style
of writing program is important because it tells program about the group of commands