# Programming Tutorials

## if, if...else and switch statements in C with samples

By: Siva in C Tutorials on 2008-08-06

If ……….else statement:

The if..else statement is a two way branch: it means do one thing or the other. When it is executed, the condition is evaluated and if it has the value `true' (i.e. not zero) then statement1 is executed. If the condition is `false' (or zero) then statement2 is executed. The if..else construction often saves an unnecessary test from having to be made.

`if (condition){statements}else{statements}`

Example:

```/*-------------------------------------------------------*/
/* To find whether a given year is leap or not */
/*-------------------------------------------------------*/

main()
{
int y, r1, r2;
printf("Enter a year");
scanf("% d", &y);
r1 = y % 4;
if (r1 = = 0)
{
r2 = y % 100;
if (r2 = = 0)
printf("The given year is not a leap year");
else
printf("The given year is a leap year");
}
else
printf("The given year is not a leap year");
}```

Logical Operators:

Comparisons are often made in pairs or even in groups and linked together with words like OR and AND. The following are the logical operators in C:

1. || [logical OR]
2. & & [logical AND]
3. ! [logical NOT]

[ || ]OR Logical Operator

```Condition-I Condition-II Result
----------- ----------- ---------
True	False	True
False	True	True
False	False	False
True	True	True```

[& &]AND Logical Operator

```Condition-I Condition-II Result
---------- ------------ ---------
True	False	False
False	True	False
False	False	False
True	True	True```

[!] NOT Logical Operator

!(True) => False

!(false) => True

Example:

```/*--------------------------------------------------------------------------------------------*/
/* To check whether a given alphabet is capital or not (using logical operator) */
/*--------------------------------------------------------------------------------------------*/

main()
{
char x;
printf("Enter an alphabet");
scanf("%c", &x);

if (x >= 65 && x <= 90)
printf("The given alphabet is capital");
else
printf("The given alphabet is not capital");
}```
`Switch Statement:`

The switch statement is another way of making a program path branch into lots of different limbs. The switch statement has the following form:

switch (integer value or constant value)

{

case 1: statement1;

break; /* optional line */

case 2: statement2;

break; /* optional line */

....

default: default statement

break; /* optional line */

}

Example:

```/* Input a direction code and print the direction name(using switch)*/

main()
{
char y;
clrscr();
printf("Enter the code");
scanf("%c", &y);
switch (y)
{
case 'N':
printf("North Direction");
break;
case 'S':
printf("South Direction");
break;
case 'E':
printf("East Direction");
break;
default:
printf("West Direction");
break;
}
}```