Lab 3 : Calculate grade from score

 
String grade;
void setup(){
  size(400,300);
  background(#000000);
  float score=79;

  cal_grade(score);
}

void cal_grade(float score){
 int x=50;
 int y=100;

  textAlign(LEFT);
  textSize(30);
  fill(#ffffff);

 if(score<50){
   grade="F";
 }else if(score>=50 && score < 55){
   grade="D";
 }else if(score>=55 && score < 60){
   grade="D+";
 }else if(score>=60 && score < 65){
   grade="C";
 }else if(score>=65 && score < 70){
   grade="C+";
 }else if(score>=70 && score < 75){
   grade="B";
 }else if(score>=75 && score < 80){
   grade="B+";
 }else if(score>=80 && score <=100){
   grade="A";
 }

  textAlign(LEFT);
  fill(#ffffff);
  text("Your score = "+score,x,y);
  text("You get grade  "+grade,x,y+100);
}