有道異常類的題不會寫，求大神解答?。。。?！
編寫一程序，從控制臺輸入一個班學生的某門課程成績，統(tǒng)計及格人數(shù)，不及格人數(shù)、平均數(shù)。為此設計一個異常類，當輸入的成績小于0分或大于100分時，拋出異常，程序中捕捉這個異常，并顯示相應的提示。
4 回答
大概就這樣，簡單的數(shù)學運算
package?page;
import?java.util.Scanner;
public?class?Test?{
????public?static?void?main(String[]?args)?{
????????final?int?M?=?3;?//?人數(shù)，三個人
????????
????????Test?test?=?new?Test();
????????
????????test.calculate(M);
????}
????public?void?calculate(final?int?M)?{
????????double?sum?=?0.0;
????????int?k?=?0;
????????
????????for(int?i?=?0;?i?<?M;?i++)?{
????????????System.out.print("學生?"?+?(i?+?1)?+?"?-?");
????????????int?score?=?this.in();
????????????sum?+=?score;
????????????if?(score?>?60)?k++;?//?及格
????????}
????????System.out.println("-----------------------");
????????System.out.println("總人數(shù)："?+?M);
????????System.out.println("及格數(shù)："?+?k);
????????System.out.println("不及格："?+?(M?-?k));
????????System.out.println("平均分："?+?(sum?/?M));
????}
????/**
?????*?throws?拋出異常類型
?????*/
????public?void?check(int?n)?throws?NumberException?{
????????/**
?????????*?自定義異常處理,?不符合條件就拋出異常
?????????*/
????????if?(n?<?0?||?n?>?100)?{
????????????throw?new?NumberException("成績必須在0-100");
????????}
????}
????/**
?????*?輸入成績
?????*/
????public?int?in()?{
????????System.out.println("輸入成績：");
????????Scanner?input?=?new?Scanner(System.in);
????????try?{
????????????int?number?=?input.nextInt();
????????????/**
?????????????*?交給自定義異常處理
?????????????*/
????????????this.check(number);
????????????/**
?????????????*?沒有拋出異常
?????????????*/
????????????System.out.println("你輸入的數(shù)據(jù)通過檢測");
????????????return?number;
????????}
????????catch?(NumberException?e)?{
????????????e.printStackTrace();
????????}
????????catch?(Exception?e)?{
????????????e.printStackTrace();
????????}
????????
????????return?0;
????}
}測試結果：
學生?1?-?輸入成績： 55 你輸入的數(shù)據(jù)通過檢測 學生?2?-?輸入成績： 66 你輸入的數(shù)據(jù)通過檢測 學生?3?-?輸入成績： 77 你輸入的數(shù)據(jù)通過檢測 ----------------------- 總人數(shù)：3 及格數(shù)：2 不及格：1 平均分：66.0
1
謝謝，看完有思路了
0
先創(chuàng)建一個異常類：?
就叫它為：NumberException
package?page;
public?class?NumberException?extends?Exception?{
????public?NumberException(String?Msg)?{
????????System.out.println("錯誤："?+?Msg);
????}
}然后在主文件中使用自定義的異常類：
package?page;
import?java.util.Scanner;
public?class?Test?{
????
????public?static?void?main(String[]?args)?{
????????
????????Test?test?=?new?Test();
????????
????????test.in();
????}
????/**
?????*?throws?拋出異常類型
?????*/
????public?void?check(int?n)?throws?NumberException?{
????????/**
?????????*?自定義異常處理,?不符合條件就拋出異常
?????????*/
????????if?(n?<?0?||?n?>?100)?{
????????????throw?new?NumberException("成績必須在0-100");
????????}
????}
????
????/**
?????*?輸入成績
?????*/
????public?void?in()?{
????????System.out.println("輸入成績：");
????????Scanner?input?=?new?Scanner(System.in);
????????
????????try?{
????????????int?number?=?input.nextInt();
????????????/**
?????????????*?交給自定義異常處理
?????????????*/
????????????this.check(number);
????????????/**
?????????????*?沒有拋出異常
?????????????*/
????????????System.out.println("你輸入的數(shù)據(jù)通過檢測");
????????}
????????catch?(NumberException?e)?{
????????????e.printStackTrace();
????????}
????????catch?(Exception?e)?{
????????????e.printStackTrace();
????????}
????}
????
}測試結果：
輸入成績： 20 你輸入的數(shù)據(jù)通過檢測
輸入成績： 120 錯誤：成績必須在0-100 page.NumberException at?page.Test.check(Test.java:22) at?page.Test.in(Test.java:38) at?page.Test.main(Test.java:11)
2
舉報
0/150
提交
取消
2016-10-05
public class Test3 {
public static void main(String[] args) {
int proNum = 5;//班級里面有20人
int jigeIndex =0;
int bujigeIndex = 0;
int avg =0;
int sum =0;
Scanner input = new Scanner(System.in);
System.out.println("***請輸入班級學生的成績***");
for(int i = 1;i<= proNum;i++){
System.out.print("請輸入第"+i+"個學生的成績:");
int chengji = input.nextInt();
System.out.println("第"+i+"個的學生的成績?yōu)?"+chengji);
if(chengji>=60){
jigeIndex ++;
}else{
bujigeIndex++;
}
try {
if(chengji<0 || chengji>100){
throw new RuntimeException("分數(shù)不正確");
}
} catch (Exception e) {
e.printStackTrace();
i--;
}
sum +=chengji;
avg = sum/proNum;
}
System.out.println("及格人數(shù)為："+jigeIndex);
System.out.println("不及格人數(shù)為："+bujigeIndex);
System.out.println("平均分為："+avg);
}
}
=====================================================
這樣是不是你要的結果？？？？？？