Thread: Help With Parameters

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];
}

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.

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

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

"hello world"

n=7

show "hello wo"?

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.