abstract class student{public : int marks;calc_grade();}class topper:public student{public : calc_grade(){return 10;}};class average:public student{public : calc_grade(){return 20;}};class failed{ int marks; };
var grade='D';var result;switch(grade){case'A':result+="10";case'B':result+=" 9";case'C':result+=" 8";case 'D'result+=" 6";default:result+=" 0";}document.write(result);