More if-else

Notice the following if statement :

if(expression)

  statement;

Here the expression can any valid expression including a relational expression. We can even use arithmetic expression in the if statement. For example all the following if statement are valid :

if(10 + 5 % 7)

  statement;

if(n=20)

  statement;

if(-15)

  statement;

if(-2.0)

  statement;

In C every expression is evaluated in terms of zero and non-zero values.
Note: that in C a non-zero value is considered to be true, whereas a 0 is considered to be false.

The default scope of the if statement is only the next statement. So, to execute more than one statement they must be written in a pair of braces