public static Grade scoreLevel(int score) {
if (score >= 90 && score <= 100) {
System.out.println("Excellent");
return Grade.A;
} else if (score >= 80 && score < 90) {
System.out.println("Good");
return Grade.B;
} else if (score >= 60 && score < 80) {
System.out.println("Average");
return Grade.C;
} else if (score >= 0 && score < 60) {
System.out.println("Bad");
return Grade.D;
}
return null;
}
将分数控制在十位以内,这样就连可以列举完,然后利用case 穿透来满足范围查询。建议不要这样做,平级if else 只会执行一个判断。 可以使用模板加策略来优化
score = score/10;
switch(score){
case 10:
case 9:
System.out.println("Excellent");
return Grade.A;
case 8:
System.out.println("Good");
return Grade.B;
case 7:
case 6:
System.out.println("Average");
return Grade.C;
case 5:
case 4:
case 3:
case 2:
case 1:
case 0:
System.out.println("Average");
return Grade.C;
default:
return null;
这种条件判断score >= 90 && score <= 100是没法去case的,if else挺好的呀