问答题
【说明】本程序实现功能：读入两个整数，第1个数除以第2个数，声明当除数为零时抛出异常类DivideByZeroException。
public class DivideByZeroException{{U}} (1) {{/U}}{
public DivideByZeroException ( ) {
super("Attcmpted to divide by zero");
}
}
import java.io. *;
public class Example {
private static int quotient(int numerator, in)/”}t denominator) throws
DivideByZeroException {
if (denominator==0)
throw{{U}} (2) {{/U}};
return(numerator / denominator);
}
public static void main(String args[]) {
int number1=0, number2=0, result0;
try{
System.out.print1n("Enter the first number:");
number1 = Integer. valueOf(Keyboard.getString()).intValue();
System.out.print1n("Enter the second number:");
number2 = Integer. Va1ueOf(Keyboard.getString()).intValue();
result = quotient(number1,number2);
}
catch (NumberFormatException e) {
System.out.print1n("Invalid integer entered!");
System. exit(-1);
}
catch ({{U}} (3) {{/U}}) {
System.out.print1n(e.to String());
System.exit(-1);
}
Systcm.out.pfint1n(number1 + "/" + number2 + "=" + result);
}
}
其中, Keyboard类的声明为:
import java.io.*;
public class Keyboard{
static BufferedReader inputStream ={{U}} (4) {{/U}}
(new InputStreamReader(System.in));
public static int getInteger() {
try(
return (Intoger.valueOf(inputStream.readLine().trim()).intValue());
} catch (Exception e) {
e.printStackTrace();
return 0;
}
}
public static String getString() {
try{
return (inputStream.readLine());
} catch ({{U}} (5) {{/U}})
{ return "0";}
}
}
【正确答案】
【答案解析】[解析]
(1)extends ArithmeticException
DivideByZeroException类从ArithmeticException类扩展而来。
(2)new DivideByZeroExeeption()
throw一个DivideByZeroException异常函数，打印错误信息。
(3)DivideByZeroException e
捕捉DivideByZeroExeeption异常信息。
(4)new BufferedReader
动态生成一个BufferedReader对象用于输入。
(5)IOException e
字符串成员函数getString中捕捉输入输出异常信息。