Help With Parameters

Hi, i am trying to write function called Add and write a main program to test it. iwant the function should take two integer parameters and return an integer result.

here is the code i have so far but i cant seem to pass them through.

Code:

---

#include <iostream>

using namespace std;
int Add(int a, int b);
int main()
{

}   
int Sum()
{   
    int a;
    int b;   
    cout << "Enter the number: ";
    cin >> a;
    cout << "Enter another number: ";
    cin >> b;
    Add(a,b);
    return 0;
}

int Add(int a,int b)
{
    Sum = Add(a,b);
    return 0;
}

---

can anyone help?

actually i think i got it.

Code:

---

#include <iostream>

using namespace std;

int Number(int a, int b);

int main()
{

cout <<"Number = " << Number(8,2) <<endl;

system ("pause");
}

int Number(int a, int b)
{
return a,b;
}

---

the only prob now is that it out puts just "2" and not both "2" and "8"

>> return a,b;
The function should probably return the result of adding the numbers.

>the only prob now is that it out puts just "2" and not both "2" and "8"
If you want to add them, then you would do:

Code:

---

  return a + b;

---

If you want to subtract them, then:

Code:

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  return a - b;

---

The idea is: perform some operation on the arguments and return the result.

Quote:

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the only prob now is that it out puts just "2" and not both "2" and "8"

---

you can only return one value, so it would probably only return the first value passed to 'return', in your case just 2. you could return a struct that contains these 2 values but you may not be familiar with them. check out the tutorials on cplusplus.com

Actually
operator , returns the last value past to it (read manual)

so

Code:

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a, b

---

is equal b

yeah thanks i managed to get that bit working now.

this is anothe part of this code that i need to add on, i dont expect anyone to do this but can someone explain what is being asked with this...

Code:

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write another function called Add which takes three
1-dimensional arrays of integers, of the same length as parameters. 
The first two arrays are added member by member and the result is returned in the third array. 
The length of the arrays is passed in ArrLen. 

Add(A,B,Result,ArrLen);

---

would be a great help thanks

ok begin by writing the function signature and as much of its body as you can. the signature is something like 'int Number(int a, int b)' in your previous post

The function should except two arrays as input
For example

Code:

---

A={1,2,3,5,10}
B={5,6,7,8,-1}
/*Its length */
ArrLen=5

---

And fill the third array with the sums of elements according to the received data
In the sample above the result should be

Code:

---

Result={6,8,10,13,9}

---

just tied adding 2 arrays together but come up with a long number and not them both added together.

this is the code i have

Code:

---

int main()
{

int a[5]={1,2,3,5,10};
int b[5]={5,6,7,8,-1};
int ArrLength=5;

ArrLength = a[5]+b[5];

cout <<ArrLength;

system("pause");

}

---

> ArrLength = a[5]+b[5];
That's a fence post error (assuming arrays start at 1). A five element array extends from 0 to 4.

> ArrLength
If you wanted the size of the array, dividing the size of the pointer by the size of one element usually works.

you cant just add two arrays together like how you did and expect to get the answer it may yield.

use a loop to go through the elements (a[0]-a[4]) and add them up (c[x] = a[x] + b[x])

i have finally got the array to add together, but i am having trouble passing them all for example i need to output it using i code line similar to

Code:

---

Sum = Add(a,b,ArrLength);

---

but i am unsure how to do this.

this is the code i have so far

Code:

---

#include <iostream>

using namespace std;

int Number(int a, int b);
int Add();

int main()
{
Add();
cout <<"Sum = " << Number(8,2) <<endl;

Sum = Add(a,b,ArrLength);

system ("pause");
}

int Number(int a, int b)
{
return a+b;
}

int Add()
{
int a[5]={1,2,3,5,10};
int b[5]={5,6,7,8,-1};
int ArrLength[5];
int i;

    for (i=0; i<5; i++)
    {
    ArrLength[i]= a[i] + b[i];
    cout <<ArrLength[i];
    }
      return ArrLength[5];
}

---

Can anyone see where i am going wrong?

Quote:

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Originally Posted by peckitt99

i have finally got the array to add together, but i am having trouble passing them all for example i need to output it using i code line similar to

Code:

---

Sum = Add(a,b,ArrLength);

---

but i am unsure how to do this.

this is the code i have so far

Code:

---

#include <iostream>
 
using namespace std;
 
int Number(int a, int b);
int Add();
 
int main()
{
Add();
cout <<"Sum = " << Number(8,2) <<endl;
 
Sum = Add(a,b,ArrLength);
 
system ("pause");
}
 
int Number(int a, int b)
{
return a+b;
}
 
int Add()
{
int a[5]={1,2,3,5,10};
int b[5]={5,6,7,8,-1};
int ArrLength[5];
int i;
 
    for (i=0; i<5; i++)
    {
    ArrLength[i]= a[i] + b[i];
    cout <<ArrLength[i];
    }
      return ArrLength[5];
}

---

Can anyone see where i am going wrong?

---

YES...and YES
1) your Add() function is declaring local variables...they will die at the end of the scope...so you will have junk values or get a compiler error when you try to refer to them in other functions
2) Why are you returning ArrLength[5] when the index value runs from 0-4...and you are not returning the array you are supposedly returning a int value only
3) uh yea...

Code:

---

#include <iostream>

using namespace std;

int Number(int, int);
int Add(int*, int*, int*);

int main()
{
        int a[5] = {1,2,3,5,10};
        int b[5] = {5,6,7,8,-1};
        int ArrLength[5];
       
        cout << "Sum = " << Number(8,2) << endl;

        int sum = Add(a,b,ArrLength);
        cout << "Sum of both arrays together is " << sum << endl;

        system ("pause");
}

int Number(int a, int b)
{
        return a+b;
}

int Add(int* a, int* b, int* ArrLength)
{
        int sum = 0;
    for(int i=0; i<5; i++)
    {
                ArrLength[i]= a[i] + b[i];
                sum += ArrLength[i];
    }

        return sum;
}

---

Quote:

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Originally Posted by peckitt99

i need to output it using i code line similar to

Code:

---

Sum = Add(a,b,ArrLength);

---

---

No, You need to output it using code line similar to what was written in your assignment description:

Code:

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Add(A,B,Result,ArrLength);

---

You should fill A and B arrays before you call the function,
you should pass in the last argument the lenght of the arrays,

and you should put as a 3rd parameter the empty array that will be filled by your function.

So after the function finishes - you just take the contents of the Result array and output it as you wish.

i got that program working and now trying to modify the previous function such that it only adds ‘n’ characters of the second parameter to the first. first of all i am having trouble passing the first output of string characters into main (i am not using any string functions as it is not allowed which is kind of a pain).

This is what i have

Code:

---


#include <iostream>

using namespace std;

int Number(int a, int b);
char Add(char*a, char*b, char*StrOut);

int main()
{
        char a[3] = {'T','i','m'};
        char b[7] = {'P','e','c','k','i','t','t'};
        char StrOut[20];
       

        cout << "Sum = " << Number(8,2) << endl;

        int sum = Add(a,b,StrOut);

        system ("pause");
}

int Number(int a, int b)
{
        return a+b;
}

char Add(char* a, char* b, char* StrOut)
{
          int i = 0;
      while (a[i] != '\0')
      {
          StrOut[i] = a[i];
          i ++;
      }
 
  StrOut[i] = ' ';
  i++;
 
  int j = 0;
  while (b[j] != '\0')
      {
          StrOut[i] = b[j];
          j ++;
          i++;
      }
  StrOut[i] = '\0';
  return StrOut[i];
}

---

Quote:

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Code:

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      while (a[i] != '\0')

---

---

You havn't put '\0' in your array, you even havn't made a room for it

use

Code:

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char a[]="Tim";

---

compiler then will do both things for you

yeah i have corrected that and changed everything but still not sure how to return StrOut to int sum = Add(a,b,StrOut); because at the moment nothing outputs.

you shouldn't

Just try to output the StrOut after you fill it inside the function

would i need another function so that it only adds the ‘n’ characters of the second parameter to the first?

or you can modify the current function after you make it working. you'll need slightly modify the second loop

when it asks for the "n characters" does it mean show characters up to n? for example

"hello world"

n=7

show "hello wo"?

I bet on "hello w" - space is also a character

As far as I've understood your objective is too take two strings and a number 'n', and add up the first 'n' characters of str2 to str1. So just add another parameter to Add, so that 'j' simply adds up to 'n'. Also, I think you've made a grave mistake in : int sum = Add(blah...). Variables can only be initialised at the beginning of main(). So int sum up there, and do sum = Add(blah...) here. Then print it. But as vart says, you could save your self a lot of space, code and time and just output code as it comes.

You don't need a StrOut then, and you can ditch 'j'. Just use 'i' again and again, and use for loops (to make things neater) for (i=0; a[i] != '/0'; i++). Also for the last condition, take the parameter 'n' and put for (i=0; i <j && a[i] != '/0'; i++) (the && bit is to take care if j > than the length of the string). You also don't have to return anything, so just make it a void function (and you don't have to have sum either).

i am unsure how to implement what you are saying as i am slightly confused about what u are saying

Ok, I'm sorry to have confused you.
I said that you should restructure your program a bit. Instead of adding these numbers to another variable StrOut (as you are doing now), and then printing the string out, you can just print the characters of the string as they come. Where ever you have a StrOut assignment (like StrOut[i] = b[i] ), you simply replace it with cout << b[i]. This saves you a lot of variables and naming and space and time and bugs.
If you can do away with strOut, then you can also not define the variables sum, and j, because they aren't required any more. Make your function Add a void function (void Add(char* a,...) ) this means that it doesn't need to return a value.
Also, you can reuse the variable 'i' in the function Add. I personally like for loops better, as they include the increment operation into it, but it's upto your taste really.
Now, if what vart says is what you want, i.e. by printing 'n' characters, you just want print 'n' character of str1 + str2 (in this case "Tim Peckitt"), then you start your 'i' = 0 at the beginning of the function Add. Then if you use for loops, ignore the first part (for (;a[i] != '/0';i++). Also, you'll have to check for the condition that i < n. So what you do is add this condition into you looping condition. So for a while loop, you'll have while (a[i] != '/0' && i < n). This includes both conditions in one. You could also put the if condition:
[code]
if (i >= n)
break;
and retain the same code as you have now.

You have made a mistake by putting the code: int sum = Add(a,b,StrOut); This is a definition, and all definitions must be done at the beginning of the code block. So restructure your code as:

Code:

---

int main()
{
    int sum;
    char a = "Tim"
    blah blah....

    sum = Add(a,b,StrOut);
    system ("pause");
}

---

That's all I had said. And as a general thing, it would be nice if you named your functions better, like Number should be something like add or addNum. And 'Add' should be something like 'cat' or 'catStr' (short for catenate). It makes it easier for people to read and understand what your code is doing.

First step - finish your original task in any possible way exactly as it is required by the assigment.
The modifications and search of other better ways to do the same thing can be done later.

My advice - read once more your assigment and try to realise what is missing in YOUR code for finishing it.

PS.
Don't use

Code:

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char a = "Tim"

---

it has 2 errors

well from my view everything works apart from the nth character. and im just getting a bit confused with everything that is getting said and how to implement everything. i know you are thinking im thick n are annoying n arquard but as u can see im a beginer at programming

Quote:

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i know you are thinking

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No, you don't
Just go on with what you are doing

i am doing it but just stuck on the nth character part.
can anyone help with this part?