Variable troubles

[SofaWolf]

I'm really new to C, and this isn't working, can someone tell me what I'm doing wrong? I'm having trouble with the variables, which I had in global before, but my teacher wants them to be local to main. My floats are

float T, speed;

And this program works fine when "float T, speed;" is directly under the include statements.

/* Calculating speed of sound from temperature 6/18/12 (CSC-150) */
#include <stdio.h>
#include <math.h>


int direct(void)
{
//directions
printf("In this program, you will need to enter the current temperature before you can get an output.\n\n"); /* Directions */
}


float temp(T)
{
//values
  printf("What is the temperature? "); /* store variable */
  scanf("%f", &T);
  return (T);
}


float calc(speed)
{
float T;
T = temp();
//calculation
speed=1086*(sqrt((5*T+297)/(247))); /* calculation */
return (speed);
}


int main()
{
float T, speed;
direct();
temp();
T = temp();
calc();
speed = calc(T);


//print


printf("\nThe speed of sound in the current temperature (%.1f) is %.1f.\n\n", T, speed); /*display result*/


return (0);
}

Any help would be greatly appreciated. Thanks!


~SW

[phantomotap]

O_o

Search for a tutorial on writing "user defined functions".

Also, search for an "indentation style" guide because your code is repellant.

Soma

[SofaWolf]

Surprisingly, I can't find much documentation on C with google. Also, this was formatted for Reddit's code display.

And yes, I know there are tutorials, what is the point of this forum if you just say, "Look it up."

[phantomotap]

I can't find much documentation on C with google.

Then your ability to search the web is horribly broken.

I suggest you start with that. I would tell you to search for "How to use Google?", but honestly if you can't find C tutorials you'd probably mess that up.

Also, this was formatted for Reddit's code display.

I don't care if it was formatted by the gods; it is still repellant and at least a few people here will refuse to help until your code looks reasonable.

Soma

[Matticus]

It looks like you're not fully grasping how to work with functions. You're using variables in your functions that aren't declared in them or passed to them (such as 'T' and 'speed').

Here's a tutorial from this site that might give you some guidance.

[nonoob]

You are asked to declare the variables local to each function. For example, in temp() should have float T. Then return T. Oh the function header should be float temp()
In main when you call it, you can do T = temp(); Then speed = calc(T); having declared speed and T in main. calc() should also return float.

[SofaWolf]

Then your ability to search the web is horribly broken.

I suggest you start with that. I would tell you to search for "How to use Google?", but honestly if you can't find C tutorials you'd probably mess that up.



I don't care if it was formatted by the gods; it is still repellant and at least a few people here will refuse to help until your code looks reasonable.

Soma

Well gee, you're helpful.

[SofaWolf]

It looks like you're not fully grasping how to work with functions. You're using variables in your functions that aren't declared in them or passed to them (such as 'T' and 'speed').

Here's a tutorial from this site that might give you some guidance.

Yeah, I didn't put the declarations back in, but I had them before at the top of the code. I'm trying to figure out how to declare them in main. Thanks for the help.

You are asked to declare the variables local to each function. For example, in temp() should have float T. Then return T. Oh the function header should be float temp()
In main when you call it, you can do T = temp(); Then speed = calc(T); having declared speed and T in main. calc() should also return float.

Thanks, I'll start editing it in the original post.

O_o

What's the point of tutorials if one expects concepts to be freshly explained every time they are questioned?

What's the point of search engines if not to reveal answers to questions already provided?

o_O

I win.

Soma

K.

[phantomotap]

And yes, I know there are tutorials, what is the point of this forum if you just say, "Look it up."

O_o

What's the point of tutorials if one expects concepts to be freshly explained every time they are questioned?

What's the point of search engines if not to reveal answers to questions already provided?

o_O

I win.

Soma

[nonoob]

Sounds like the teacher did not do an adequate job explaining basic concepts such as local variables, parameter passing, and value returning.

[tomás]

I think that the only thing you want is the program working:

/* Calculating speed of sound from temperature 6/18/12 (CSC-150) */
#include <stdio.h>
#include <math.h>
void direct()
{ 
/*directions*/
printf("In this program, you will need to enter the current temperature before you can get an output.\n\n"); /* Directions */
}
float temp()
{
/*values*/
  float T;
  printf("What is the temperature? "); /* store variable */
  scanf("%f", &T);
  return T;
}
float calc(float T)
{ 
/*calculation*/
float speed;
speed=1086*(sqrt((5*T+297)/(247))); /* calculation */  
return speed;
}
int main()
{
direct();
float T;           T=temp();
float speed;       speed=calc(T);
printf("\nThe speed of sound in the current temperature (%.1f) is %.1f.\n\n", T, speed); /*display result*/
return (0);
}

Dont leave so many unwritten lines haha makes reading a program complicated XD

[phantomotap]

Sounds like the teacher did not do an adequate job explaining basic concepts such as local variables, parameter passing, and value returning.

Considering that the originator's efforts to solve his problem consisted of literally applying your comments without thought to his code I'd say they he only wants a solution instead of education.

Dont leave so many unwritten lines haha makes reading a program complicated

You are an idiot.

Don't do peoples work for them at this forum. If you enjoy that sort of thing find yourself a place for that.

This, again, is why I'm not a moderator; you'd already be temp-banned.

Soma

[SofaWolf]

Okay, I updated the code in the original post.

[SofaWolf]

I'd say they he only wants a solution instead of education.

I would like a solution. A solution would serve to benefit the education.

Anyway, I'm used to people like you. Someone always has 2-7k posts on a forum and is a complete ass. They usually try to post in every topic, and more likely than not, they get banned eventually.

[tomás]

Sorry I thought that I may helped him by making some changes in his program so he could see them and realise what his problem was.
It´s obvious I am new to this, but not an idiot...