Chapter 12.7, Problem 12.7.1CP

a.

Program Plan Intro

Finally block:

Finally block contains block of code and the block is executed after a try-catch block.

• If there is no errors in try block, finally statement is executed after try block executed.
• If there is error in try block, then catch block caught the exception, rest of try block is skipped, and then executes the finally statement.
• If there is error in try block, then catch block does not caught that exception, rest of try block is skipped, executes only finally statement, and then skip the rest of the code.
• Thus, finally block handle such case and it contains block of statement. Once try-catch block gets executed, finally block is executed.

Rethrowing the exception:

• An exception can be rethrown by a catch statement because; it can catch and handled by another catch statement.
• It allows many handlers to access the exception.
• However, the rethrown exception should not recaught by the same exception and should propagate to next catch statement.

In following class, first catch statement catches exception and rethrows it to another catch statement:

class Rethrow_exp

{

try

{

//... Try block statement

}

Catch statement rethrows the exception.

catch(Excep_type excep_obj)

{

//... Catch block statement

// Rethrow the exception

throw excep_obj

}

//...

}

Catch statement catches the rethrown the exception.

class rethrow_main

{

//...

catch(Excep_typeexcep_obj)

{

// Recatch block statement catches rethrown //exception

}

}

Therefore, an inner catch rethrow an exception to an outer catch.

Given code:

//Try block

try

{

statement1;

statement2;

statement3;

}

//Catch block

catch (Exception1 ex1)

{

}

//Catch block

catch (Exception2 ex2)

{

}

//Finally block

finally

{

statement4;

}

statement5;

b.

Program Plan Intro

Finally block:

Finally block contains block of code and the block is executed after a try-catch block.

• If there is no errors in try block, finally statement is executed after try block executed.
• If there is error in try block, then catch block caught the exception, rest of try block is skipped, and then executes the finally statement.
• If there is error in try block, then catch block does not caught that exception, rest of try block is skipped, executes only finally statement, and then skip the rest of the code.
• Thus, finally block handle such case and it contains block of statement. Once try-catch block gets executed, finally block is executed.

Rethrowing the exception:

• An exception can be rethrown by a catch statement because; it can catch and handled by another catch statement.
• It allows many handlers to access the exception.
• However, the rethrown exception should not recaught by the same exception and should propagate to next catch statement.

In following class, first catch statement catches exception and rethrows it to another catch statement:

class Rethrow_exp

{

try

{

//... Try block statement

}

Catch statement rethrows the exception.

catch(Excep_type excep_obj)

{

//... Catch block statement

// Rethrow the exception

throw excep_obj

}

//...

}

Catch statement catches the rethrown the exception.

class rethrow_main

{

//...

catch(Excep_typeexcep_obj)

{

// Recatch block statement catches rethrown //exception

}

}

Therefore, an inner catch rethrow an exception to an outer catch.

Given code:

//Try block

try

{

statement1;

statement2;

statement3;

}

//Catch block

catch (Exception1 ex1)

{

}

//Catch block

catch (Exception2 ex2)

{

}

//Finally block

finally

{

statement4;

}

statement5;

c.

Program Plan Intro

Finally block:

Finally block contains block of code and the block is executed after a try-catch block.

• If there is no errors in try block, finally statement is executed after try block executed.
• If there is error in try block, then catch block caught the exception, rest of try block is skipped, and then executes the finally statement.
• If there is error in try block, then catch block does not caught that exception, rest of try block is skipped, executes only finally statement, and then skip the rest of the code.
• Thus, finally block handle such case and it contains block of statement. Once try-catch block gets executed, finally block is executed.

Rethrowing the exception:

• An exception can be rethrown by a catch statement because; it can catch and handled by another catch statement.
• It allows many handlers to access the exception.
• However, the rethrown exception should not recaught by the same exception and should propagate to next catch statement.

In following class, first catch statement catches exception and rethrows it to another catch statement:

class Rethrow_exp

{

try

{

//... Try block statement

}

Catch statement rethrows the exception.

catch(Excep_type excep_obj)

{

//... Catch block statement

// Rethrow the exception

throw excep_obj

}

//...

}

Catch statement catches the rethrown the exception.

class rethrow_main

{

//...

catch(Excep_typeexcep_obj)

{

// Recatch block statement catches rethrown //exception

}

}

Therefore, an inner catch rethrow an exception to an outer catch.

Given code:

//Try block

try

{

statement1;

statement2;

statement3;

}

//Catch block

catch (Exception1 ex1)

{

}

//Catch block

catch (Exception2 ex2)

{

throw ex2;

}

//Finally block

finally

{

statement4;

}

statement5;

d.

Program Plan Intro

Finally block:

Finally block contains block of code and the block is executed after a try-catch block.

• If there is no errors in try block, finally statement is executed after try block executed.
• If there is error in try block, then catch block caught the exception, rest of try block is skipped, and then executes the finally statement.
• If there is error in try block, then catch block does not caught that exception, rest of try block is skipped, executes only finally statement, and then skip the rest of the code.
• Thus, finally block handle such case and it contains block of statement. Once try-catch block gets executed, finally block is executed.

Rethrowing the exception:

• An exception can be rethrown by a catch statement because; it can catch and handled by another catch statement.
• It allows many handlers to access the exception.
• However, the rethrown exception should not recaught by the same exception and should propagate to next catch statement.

In following class, first catch statement catches exception and rethrows it to another catch statement:

class Rethrow_exp

{

try

{

//... Try block statement

}

Catch statement rethrows the exception.

catch(Excep_type excep_obj)

{

//... Catch block statement

// Rethrow the exception

throw excep_obj

}

//...

}

Catch statement catches the rethrown the exception.

class rethrow_main

{

//...

catch(Excep_typeexcep_obj)

{

// Recatch block statement catches rethrown //exception

}

}

Therefore, an inner catch rethrow an exception to an outer catch.

Given code:

//Try block

try

{

statement1;

statement2;

statement3;

}

//Catch block

catch (Exception1 ex1)

{

}

//Catch block

catch (Exception2 ex2)

{

throw ex2;

}

//Finally block

finally

{

statement4;

}

statement5;