if and statement

if and statement

The  if   statement controls conditional branching. The body of an if statement is executed if the value of the expression is nonzero. The syntax for the if statement has two forms.

Syntax

Selection-statement:

if ( expression ) statement

if ( expression ) statement else statement

In both forms of the if statement, the expressions, which can have any value except a structure, are evaluated, including all side effects.

In the first form of the syntax, if expression is true (nonzero), statement is executed. If expression is false, statement is ignored. In the second form of syntax, which uses else, the second statement is executed if expression is false. With both forms, control then passes from the if statement to the next statement in the program unless one of the statements contains a break, continue, or goto.

The following are examples of the if statement: 

if ( i > 0 )

    y = x / i;

else

{

    x = i;

    y = f( x );

}