java编写程序 4. 编写程序，从键盘输入学生成绩，根据成绩判断：如果成绩小于60，则输出“不及格”；若成

public static void main(String[] args) throws Exception {
System.out.print("请输入成绩：");
Scanner sc = new Scanner(System.in);
String str = sc.nextLine();
try {
int score = Integer.parseInt(str);
if (score >= 0 && score < 60){
System.out.println("不及格");
} else if (score >= 60 && score < 75){
System.out.println("及格");
} else if (score >= 75 && score < 90) {
System.out.println("良");
} else if (score >= 90 && score <= 100){
System.out.println("优");
} else {
System.out.println("成绩无效");
}
} catch (NumberFormatException e){
System.out.println("成绩输入错误");
}
}本回答被提问者采纳

import java.util.Scanner;

public class ScoreJudge {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);
double score = 0;

try {
System.out.print("请输入成绩：");
score = sc.nextDouble();
} catch (NumberFormatException nbFmtExp) {
System.out.println("成绩输入错误");
return;
}

if (score < 0 || score > 100) {
System.out.println("成绩无效");
}

if (score >= 0) {
if (score < 60) {
System.out.println("不及格");
} else if (score < 75) {
System.out.println("及格");
} else if (score < 90) {
System.out.println("良");
} else if (score <= 100) {
System.out.println("优");
}
}

}
}