Decision making in C Programming

C  programming  language  assumes  any non-zero and non-null values  as true, and if it is  either zero or null, then it is assumed as false value.C  programming  language  provides  the  following  types  of  decision-making statements.

•   if Statement 

An if statement  consists  of  a  Boolean  expression  followed  by  one  or  more statements.

• if…else Statement 

An if statement  can  be  followed  by  an  optional else statement, which  executes when the Boolean expression is false.
Syntax 
The syntax of an if...else statement in C programming language is:

•  if...else if...else Statement 

An if statement can be followed by an optional else  if...else statement, which is very useful to test various conditions using single if...else if statement.
Syntax 

•  Nested if Statements 

It is always legal in C programming to nest if-else statements, which means you can use one if or else if statement inside another if or else if statement(s).
Syntax 
The syntax for a nested if statement is as follows:

                              

•  Switch Statement 

A switch statement allows a variable  to be  tested  for equality against a  list of values.  Each  value  is  called  a  case,  and  the  variable  being  switched  on  is checked for each switch case.
Syntax 
The syntax for a switch statement in C programming language is as follows: