編寫一程序，從控制臺(tái)輸入一個(gè)班學(xué)生的某門課程成績(jī)，統(tǒng)計(jì)及格人數(shù)，不及格人數(shù)、平均數(shù)。為此設(shè)計(jì)一個(gè)異常類，當(dāng)輸入的成績(jī)小于0分或大于100分時(shí)，拋出異常，程序中捕捉這個(gè)異常，并顯示相應(yīng)的提示。
2016-10-05
大概就這樣，簡(jiǎn)單的數(shù)學(xué)運(yùn)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(gè)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(xué)生?"?+?(i?+?1)?+?"?-?");
????????????int?score?=?this.in();
????????????sum?+=?score;
????????????if?(score?>?60)?k++;?//?及格
????????}
????????System.out.println("-----------------------");
????????System.out.println("總?cè)藬?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(jī)必須在0-100");
????????}
????}
????/**
?????*?輸入成績(jī)
?????*/
????public?int?in()?{
????????System.out.println("輸入成績(jī)：");
????????Scanner?input?=?new?Scanner(System.in);
????????try?{
????????????int?number?=?input.nextInt();
????????????/**
?????????????*?交給自定義異常處理
?????????????*/
????????????this.check(number);
????????????/**
?????????????*?沒(méi)有拋出異常
?????????????*/
????????????System.out.println("你輸入的數(shù)據(jù)通過(guò)檢測(cè)");
????????????return?number;
????????}
????????catch?(NumberException?e)?{
????????????e.printStackTrace();
????????}
????????catch?(Exception?e)?{
????????????e.printStackTrace();
????????}
????????
????????return?0;
????}
}測(cè)試結(jié)果：
學(xué)生?1?-?輸入成績(jī)： 55 你輸入的數(shù)據(jù)通過(guò)檢測(cè) 學(xué)生?2?-?輸入成績(jī)： 66 你輸入的數(shù)據(jù)通過(guò)檢測(cè) 學(xué)生?3?-?輸入成績(jī)： 77 你輸入的數(shù)據(jù)通過(guò)檢測(cè) ----------------------- 總?cè)藬?shù)：3 及格數(shù)：2 不及格：1 平均分：66.0
謝謝，看完有思路了
先創(chuàng)建一個(gè)異常類：?
就叫它為：NumberException
package?page;
public?class?NumberException?extends?Exception?{
????public?NumberException(String?Msg)?{
????????System.out.println("錯(cuò)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(jī)必須在0-100");
????????}
????}
????
????/**
?????*?輸入成績(jī)
?????*/
????public?void?in()?{
????????System.out.println("輸入成績(jī)：");
????????Scanner?input?=?new?Scanner(System.in);
????????
????????try?{
????????????int?number?=?input.nextInt();
????????????/**
?????????????*?交給自定義異常處理
?????????????*/
????????????this.check(number);
????????????/**
?????????????*?沒(méi)有拋出異常
?????????????*/
????????????System.out.println("你輸入的數(shù)據(jù)通過(guò)檢測(cè)");
????????}
????????catch?(NumberException?e)?{
????????????e.printStackTrace();
????????}
????????catch?(Exception?e)?{
????????????e.printStackTrace();
????????}
????}
????
}測(cè)試結(jié)果：
輸入成績(jī)： 20 你輸入的數(shù)據(jù)通過(guò)檢測(cè)
輸入成績(jī)： 120 錯(cuò)誤：成績(jī)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)
舉報(bào)
2016-10-05
public class Test3 {
public static void main(String[] args) {
int proNum = 5;//班級(jí)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(qǐng)輸入班級(jí)學(xué)生的成績(jī)***");
for(int i = 1;i<= proNum;i++){
System.out.print("請(qǐng)輸入第"+i+"個(gè)學(xué)生的成績(jī):");
int chengji = input.nextInt();
System.out.println("第"+i+"個(gè)的學(xué)生的成績(jī)?yōu)?"+chengji);
if(chengji>=60){
jigeIndex ++;
}else{
bujigeIndex++;
}
try {
if(chengji<0 || chengji>100){
throw new RuntimeException("分?jǐn)?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(jié)果？？？？？？