The if statement is the java's conditional branch statement. The general form of if statement is :

if(condition)
statement ;
or
if(condition)
{
statement 1;
statement 2;
.
.
.
statement n;
}

where the condition can be any expression that produces a value true or false. If the condition is true, the statement that follows the if is executed. Otherwise the statement will not execute.
Or, if it contains a block of statement, then if the condition is true then all the statements will execute, and if the condition is false then the control execute the second statement onwards.

Example:

class IfDemo
{
	public static void main(String[] args)
	{
		int a=15;
		if(a<20)
		System.out.println("JavaRace");
	}
}

Output
JavaRace