Lab Exception Handling CSIS-1410 Download LabExceptionHandling.java Run the prog

Question

Lab Exception Handling CSIS-1410 Download LabExceptionHandling.java Run the program and enter the number 10. An exception will be thrown. Look at the stack trace to find the type of the exception: _____________________________________________ Then fix the problem. After the first problem has been fixed run the program again. This time enter 2.5 as number. An exception will be thrown. Type of the exception: _____________________________________________ Which is the last code statement in ‘my’ code that was (partially) executed before the exception was thrown? (this it the first entry of ‘my’ code in the stack trace) _____________________________________________ Change the method numberFromUser so that it keeps reading in numbers until the user provides a valid integer. Every time the user enters something invalid (e.g. a floating point number, a string etc.) a message should be printed. (e.g. The number entered needs to be a whole number.) Where should the Scanner variable input be initialized? Iinside or outside of the loop? Does it matter? See answer below. Run the program again. Enter first 2.5, then “zero”, and then 0 when prompted for a number. An exception will be thrown. Type of the exception: _____________________________________________ Which is the last code statement in ‘my’ code that was (partially) executed before the exception was thrown? (the first entry of ‘my’ code in the stack trace) _____________________________________________ This time we don’t fix the probem in the body of the method that caused the exception. Instead we re-throw the exception. How can that be done? Check whether the parameter is 0. If that is the case throw an IllegalArgumentException. As you throw the new exception provide some information about the problem by adding a message: “ Can’t calculate 7 % 0 “ as argument to the IllegalArgumentException constructor. Run the program again. This time enter 0 as number An exception will be thrown. Type of the exception: _____________________________________________ Which is the last code statement in ‘my’ code that was (partially) executed before the exception was thrown? _____________________________________________ Notice that the message Can’t calculate 7 % 0 is displayed as well as the stack trace Change the main method so that all the code from main is wrapped in a try block. Add a catch block that catches any exception. In the catch block print the following message: A problem occurred: followed by the message from the exception. Hint: Every exception inherits the method getMessage from Throwable. This method returns a string that includes the message that should be displayed. Run the program an enter 2.5 then hallo then 0 SAMPLE OUTPUT: number: 2.5 The number entered needs to be a whole number. number: hallo The number entered needs to be a whole number. number: 0 Answer: The Scanner variable should be initialized outside of the loop. Why? One instance of Scanner is enough to read in multiple numbers. Creating a new Scanner instance for every number read would be inefficient .

Code provided:

Explanation / Answer

1.
The exception is:
java.util.IllegalFormatConversionException

2.
Correct the exception by parsing the variables to float while printing with the $f specifier, like below.
System.out.printf("7 %% %.1f = %.1f", (float)digit, (float)result);

3.
The type pf exception is:
java.util.InputMismatchException

4.
The last statement being run before the exception is:
return input.nextInt();

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