Need help with Changing variables

[supersaiyan1]

code:

var score : real for test_num : 1 .. 5     put "Enter the score for Test ",  test_num, "."     loop         get score         exit when score >= 0 and score <= 100         put "The mark is out of range..."         put "Please enter a valid mark."     end loop     put "Your mark for Test ", test_num, " is ", score / 100 : 4 : 1 end for

k my program
when i enter letter instead of number, it crashes
is there a way to make it stop crashing
if yes can u plz explain me

Code tags added by your friendly neighborhood spiderm... err... mod.

[uberwalla]

ok i cant really think of it right now but im pretty sure its possible, ima go watch t.v and ill try to think about it a bit. and by the way when u put ur code in ur post plz make use of the code tags and indenting ur code in turing so that it is easier to read.

[[Gandalf]]

Welcome to compsci.ca!

The solution to your problem lies in error proofing, which was covered in Cervantes' String Manipulation Tutorial. In essence, you will read in the integer as a string, and then convert that string back to an integer if it doesn't contain any non-numerical characters. Read through it, and you should be able to accomplish what you seek.

And yes, next time make sure to put your code inside [ code ] [ /code ] tags (without the spaces).

[sweetiechic]

k well this is the way I learned how to bulletproof my work:

code:

procedure getscore(var number: int) var input: string    loop       get input       exit when strintok (input)       put "Not a possible score. Please enter a test score:"..    end loop number:= strint(input) end getscore

and then when u want to get a score use 'getscore' instead of 'get'

[Clayton]

that is in essene correct, perhaps you should put that into a function, generally, whenever you can use a function over a procedure, do it.

[sweetiechic]

ohh ok, I thought you couldn't output anything in a function though..? and there's a put statement in the procedure

[Silent Avenger]

Functions do have outputs, otherwise they wouldn't be of much use.

[[Gandalf]]

Silent Avenger wrote:

Functions do have outputs, otherwise they wouldn't be of much use.

This statement is no doubt confusing.

While it is possible to output something in a function, the main point of a function is to return a value. So instead of having:

code:

proc timesTwo (n : int)     put n, " times two is: ", n * 2 end timesTwo timesTwo(5)

You would have:

code:

fcn timesTwo (n : int) : int     result n * 2 end timesTwo put "5 times two is: ", timesTwo(5)