shortening a program?

[butterfly21]

Is there anyway to shorten a program by calling another function i could write, instead of repeating the same section over and over??

thanks

[Banfa]

Yes find a section of code that is repeated, move that code to a function and then replace all the places that section of code is used with a call to the function.

This will probably produce short but slightly slower code.

You can be clever and find sections that do the same thing on different data and create a function that accepts parameters in order to pass that different data into the function.

[butterfly21]

Yes find a section of code that is repeated, move that code to a function and then replace all the places that section of code is used with a call to the function.

This will probably produce short but slightly slower code.

You can be clever and find sections that do the same thing on different data and create a function that accepts parameters in order to pass that different data into the function.

Thank you for a quick reply.
Could you tell me how i call a function? And if i put the repeated part of the code in another progam, do i write it the same way?
thanks

[chiefs]

Is there anyway to shorten a program by calling another function i could write, instead of repeating the same section over and over??

thanks

A very easy way to do this is the goto statement:

For Example:

goto NAME_1;

Follow the program & you will understand as long as this is in C++ and not Visual C++

// Program Q1:Q1.cpp
# include <iostream.h>
# include <stdio.h>

main()
{

char name[30];
char a;
char pw1;
char pw2;

printf ("What is your name?");
scanf ("%s", &name);
printf ("High (%s)\n\n", name);
printf ("Is this correct?");
scanf ("%s", &a);
if ((a == 'y') || (a == 'Y'))
goto PASS_WORD1;
else
goto NAME_1;

NAME_1:
printf ("Please Re-enter name!");
scanf("%s",&name);
printf ("Okay, %s\n\n", &name);
goto PASS_WORD1;

[manontheedge]

you can use GOTO, but in my experiences, GOTO is extremely frowned upon in C and C++.

i think you're looking for FUNCTIONS. It all depends on how you write your code on how you use functions. If you have classes, then you can DECLARE all of your functions in the header file, and DEFINE them in a .cpp file.

if you just wanna bunch everything in one file, then you can declare functions before or after main(), and define them in main(), and call them there as well.

if this is at all confusing sounding, it's really not once you see some examples and try it yourself.

i don't have time to type up an example, but if you need some answers quickly, look around on the internet for functions.

[Banfa]

Here is an example of a small program that defines and calls 1 function and also calls 1 library function.

I strongly recomend you don't use GOTO until you truely understand the C/C++ language in full and then you probably shouldn't use GOTO.

#include <stdio.h>
 
void Swap(unsigned &a, unsigned &b);
 
int main()
{
    unsigned a = 5;
    unsigned b = 10;
 
    printf("a = %u, b = %u\n", a, b);
 
    Swap(a, b);
 
    printf("a = %u, b = %u\n", a, b);
    return 0;
}
 
void Swap(unsigned &a, unsigned &b)
{
    a ^= b;
    b ^= a;
    a ^= b;
}