如图
if(score>=90 && <=100){
System.out.println("A");
}else if(score>=80 && score <=89){
System.out.println("B");
}else if(score>=70 && score <=79){
System.out.println("C");
}else if(score>=60 && score <=69){
System.out.println("D");
}else if(score>=0 && score <=59){
System.out.println("E");
}else{
System.out.println("不合法的分数");
}
public static void main(String[] args) {
int score = 95;
if(score>=90 && score<=100){
System.out.println("A级");
}else if(score>=80 && score<=89){
System.out.println("B级");
}else if(score>=70 && score<=79){
System.out.println("C级");
}else if(score>=60 && score<=69){
System.out.println("D级");
}else if(score>=0 && score<=59){
System.out.println("E级");
}else{
System.out.println("不合法");
}
}