The main() method of a Java program has the following declaration and
statement:
public class Q9
{
public static void main(String [] args)
{
char b = 'B';
double a = 11.11;
System.out.println(b / a);
}
}
What would happen when the programmer attempted to compile and run
this code?
(A) The code would not compile: there would be a compiler error
(B) The code would compile and run: the output seen on the screen
would be: B/11.11
(C) The code would compile and run: the output seen on the screen
would be: b/a
(D) The code would compile and run: there would be a runtime error
(E) None of the above answers are correct
D是对的
代码会编译并运行,但是会出现运行时错误
变量b是char类型,变量a是double类型。当表达式b / a被计算时,b的char值被提升为double值。然而,将double除以零会导致运行时算术异常
。。。有时间在这里等答案,怎么不自己运行一下,答案不就知道了
答案:如果Java代码存在错误,编译器会提示错误信息,并无法编译成功。如果强行使用存在错误的代码进行运行,会出现运行时错误。因此,选项(A)和(D)都是正确的。具体错误信息和处理方式,需要根据错误类型进行分析和解决。常见的错误类型包括语法错误、逻辑错误、空指针异常等。处理方式包括排查错误原因、修改代码错误、加入错误判断等。以下是一个简单的示例代码,演示了Java代码错误和异常处理的方式:
public class Test {
public static void main(String[] args) {
int[] arr = new int[3];
System.out.println(arr[3]); // 数组越界错误
try {
int c = 1 / 0; // 算术错误
} catch (ArithmeticException e) {
System.out.println("捕获到异常:" + e.getMessage());
} finally {
System.out.println("执行 finally 块");
}
}
}
以上代码中包含了两个常见错误类型,一个是数组越界错误,一个是算术错误。在代码中可以加入对错误的判断处理,比如使用 try-catch-finally 语句块来捕获异常并进行处理,以避免程序崩溃。