尝试并最终给出不带return语句的异常，但是在方法中编写return语句时也没有异常 [英] try and Finally giving exception with no return statement , but there is no exception when return statement is written in method

问题描述

请解释为什么异常出现在第一个程序中而不出现在第二个程序中.

Please explain why Exception comes in first program but not in second program.

1)在读取方法中没有return语句

1) without return statement in read method

class Example
{   
    public static void read()
    {
        try
        {
             int i = 9/0;
        }
        finally
        {
              System.out.println("This proogram is giving exception");
        }       
    }

    public static void main(String[] fel)
    {
         read();
    }
}

2)在read方法中带有return语句

2)with return statement in read method

class Example
{   
    public static void read()
    {
         try
         {
               int i = 9/0;
         }
        finally
        {
               System.out.println("This proogram is not giving exception");
               return;
        }       
    }

    public static void main(String[] fel)
    {
          read();
    }
}

推荐答案

最终不要在内部使用分支语句(return，goto)，因为执行此类语句会使最终要执行的其他指令无效.

Branching statements(return ,goto ) should no be used inside finally because execution of such statement nullifies other instructions which are executed before finally.

Java语言规范说:如果try块的执行由于其他任何原因R突然完成，那么将执行finally块，然后可以选择:

The Java Language Specification says : If execution of the try block completes abruptly for any other reason R, then the finally block is executed, and then there is a choice:

1. 如果finally块正常完成，则try语句由于原因R突然完成.
2. 如果finally块由于原因S突然完成，则try语句由于原因S突然完成(并且原因R被丢弃).

注意-在finally块中的return语句将导致丢弃任何可能在try或catch块中引发的异常.

Note - A return statement inside a finally block will cause any exception that might be thrown in the try or catch block to be discarded.

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