Thread: entering arrays

1234

Hello and welcome to the C programming forums. Hopefully staying here a bit will help a lot with your understanding of the language.
To declare an array, requires knowledge of two things the array type, and size.
Let's say we need to store 10 numbers.

Code:

int number[10];

This allocates room for ten signed numbers. The type is int which on most modern machines is either 32, or 64 bits wide and the length is 10.
Reading in input from the user is a bit more tricky. Most will tell you to use buffers and parse the numbers and various other advice to handle improper input. For demonstrations purposes i will use a plain old scanf.

Code:

int i;
for(i=0; i<10; i++)
{
    scanf("&#37;d", &number[i]);
}

Asuming the input is correct, it will populate the array with values.
To search for the highest and lowest values, is simply a matter of logic rather than array features.
The logic is to maintain two extra variables that correspond to the maximum and the minimum. Then initialize those variables to the extreme opposites, meaning the maximum to the minimum possble number and minimum to the maximum possible number that an int can hold. (These values are defined as constants in the <limits.h> header file, and with intuitive names INT_MIN and INT_MAX.)
Then for every element of 'number' compare it to the current minimum and maximum, and should the element be less than the current minimum that element is the current minimum, and use the same logic to update the current maximum.
After all elements of the array have been accessed, the minimum and the maximum have been found.

I would give real source code, but your post appears to be a masked homework post. Surely, if you are a trainee teacher you have read code that deals with trivial tasks.

Are you sure you are/should be a teacher? This code is full of bugs and has very poor indentation.
And as for that matter, do you use C99 or C89?

>i am a traniee teacher
What are you teaching? If it's C or programming in general then you've got to do some learning before you're qualified to be a teacher. I would expect any beginner to C to be able to solve this problem with ease after maybe two weeks of study.

>And as for that matter, do you use C99 or C89?
C89. How do I know? C99 doesn't allow implicit function declarations anymore, so failure to include stdlib.h or manually declare the system function would throw an error on a conforming C99 compiler.

But then again, it might just be a problem on the teacher's part that the appropriate header wasn't included. I'm thinking this is just "whim of the time" code, just whipped up to be posted here quickly.

I was reluctant whether i could teach. I am not doing it as a profession, but rather part time. This site was a great help, in the way that it taught me where to expect the question, and to remember my own questions when i was learning. Oh and also how to formulate the answer so that it might be clean and correct, at least most of the times.

Dave: You need serious reading. You can not expect to win the respect of students if they outsmart you. Also, i would consider it very important to know what i am talking about, lest not talk at all. Half-spoken words are worse than not spoken at all.
The code you present shows that you need to start from scratch.
You can not form variable declarations ( there is not a correct array declaration in your code), you don't understand well what is a statement.
Your for loop should operate on multiple statements, but you haven't grouped them between {}, so that it has a chance to do so.
If as you can say, you can read C code, then do so. And try to be as simple as possible for the moment. Keep your statements clean, indent, think before you write.
Ask when something is confusing you.
Remember in programming the most important thing above all, is to understand how the flow of the program goes, being able to form it in your mind for short code parts will reassure the validity of the solution without having to revert to program proof theories. Language syntax comes at the next phase.

Originally Posted by xuftugulus

You can not form variable declarations ( there is not a correct array declaration in your code), you don't understand well what is a statement.

You can in C99, but I'm not sure if that's what you're hinting at.

Probably the biggest error in the code is that the array is initialized with an uninitialized variable i. Will probably cause the program to crash as soon as it starts. This is assuming it would be compiled under C99, otherwise it wouldn't compile at all.

1234

I don't think you should cover programming if you can't write proper code. Sorry.
C is a complex language where you can't just do as you please. But that should hold true for any language, though.

For reference, this is the reply I replied to:

Originally Posted by davesmaith

gents i plan to teach technology, covering all aspects my specialist subject is food
i a a fist year degree student and one modue i have to cover is programming
please understand this is not my subject area and will require suport not criticism