Please got through the following code snippet.

class NanTest {

    public static void main ( String args [ ] ) {
        int intX = 10 ; // line 1
        float floatX = 10 ; // line 2
        double doubleX = floatX / 0 ; // line 3
        double doubleY = intX / 0 ; // line 4
        System . out . println ( doubleX == doubleY ) ; // line 5
    }
}

It  throws exception on line 4 but not on line 3.
Could anyone please explain this.