No error, but still doesn't work!

Hey everybody.

I am new to this forum, and i just started programming. I have been trying to make some different simple programs, but when i tried this, it just wouldn't put out a number at the end of the programming. I would appreciate some help. ( Also if you have some tricks to make some of the things in the program more simple plz tell me )

Here is the code.

Code:

#include <iostream>

using namespace std;

 double y;               // Antal genstande!
 double x;               // Vægt!
 double d;
 double j;

int main()
{
 cout<<"                            PROMILLE UDREGNER  \n                               - af Alek -";
cin.get();
cout<<"Indsaet din vaegt i kg  :";
d = 0.68 * x;
cin>> x;
cin.ignore();
cout<<"Indsaet antal indtagede genstande  :";
j = 12 * y;
cin>> y;
cin.ignore();
cout<<"Din promille er:   ";
cout<< j / d;
cin.get();
}

Thx!

BTW, sorry if it is a bit messy .

The problem occurs when i want the last expression ( cout<< j / d ) to be shown off in the program, but it doesn't put out numbers, instead it writes something strange. If anybody knows what to do / or if i made an error ( which i probably did, please tell me )

P.S. The language is danish, might look a bit strange to some ppl.

Code:

d = 0.68 * x;
cin>> x;

//...

j = 12 * y;
cin>> y;

Both are backwards. You are calculating values before prompting the user. Swap those lines and you should be ok.

What kinds of things does it write?

I don't think x (and j) is defined here:

d = 0.68 * x;

EDIT - Damn. Beaten.

But seeing as I'm exceedingly bored:

Code:

#include <iostream>
using namespace std;

int main( void )
{
 	double y;               // Antal genstande! - You should probably not use Globals
 	double x;               // Vægt!
 	double d;
 	double j;

	cout<<    "                            PROMILLE UDREGNER  ";
	cout<< "\n                               - af Alek -      ";

	cin.get();


	cout<<"Indsaet din vaegt i kg  :";
	cin >> x;

	d = 0.68 * x;

	cin.ignore();

	cout<<"Indsaet antal indtagede genstande  :";
	cin >> y;

	j = 12 * y;

	cin.ignore();



	cout<<"Din promille er:   ";
	cout<< j / d;

	cin.get();

	return 42;	// Or 0, or whatever you want. 
}

You don't initialize the variables to 0.. so it just grabs what ever was in the memory where the variable is placed.

[edit] double pwnt =( [/edit]

Hey.. You guys were right . Just switched cin>> x; with the function, cuz i had to declare the function before, else the value of the function would be ignored. Thx

A good practice though would be to initialize all your variables to a value, so you can find mistakes like this easier. Make all your int/float/long/double/ect init to 0 and string/char[] to ""

Code:

int anInt = 0;
long aLong = 0;
std::string aString = "";
char aChar[10] = "";

That way you can't accidentally use garbage values like you were.

I couldn't agree more! (I would put more of these '!', there, but you told someone today that they don't add any more meaning)

I'll do that next time!
Now i want to make some comments, that depends on the value i get from the last function ( j / d ). But i doesn't seem like i can do that, the comment is always the same, no matter what value i get. I am allowed to make the value be between to other values like i have done right? And one last thing ? what do i need the return 0; (or whatever value i like) function for?

Code:

#include <iostream>
using namespace std;

 	double y;               // Antal genstande! - You should probably not use Globals
 	double x;               // V&#230;gt!
 	double d;
 	double j;

int main()
{


	cout<<    "                            PROMILLE UDREGNER  ";
	cout<< "\n                               - af Alek -      ";

	cin.get();


	cout<<"Indsaet din vaegt i kg  : ";
	cin>> x;

	d = 0.68 * x;

	cin.ignore();

	cout<<"Indsaet antal indtagede genstande  : ";
	cin>> y;

	j = 12 * y;

	cin.ignore();



	cout<<"Din promille er:   ";
	cout<< j / d;
    
    if ( 0.2 <= ( j / d ) <= 0.5 ) {
    cout<<"\n Oejets evne til hurtigt at fokusere og omstille sig fra lys til moerke forringes.";
}
    else if ( 0.5 <= ( j / d ) <= 0.8 ) { 
    cout<<"\n Evnen til p&#229; en gang at opfatte situationer og samtidig udfoere praecise bevaegelser begynder at forringes, ligesom synsvinklen indsnaevres.";
}
    else if ( 0.8 <= ( j / d ) <= 1.0 ) {
    cout<<"\n Nedsat koordinationsevne og oeget reaktionstid.";
}
    else if ( 1.0 <= ( j / d ) <= 1.5 ) {
    cout<<"\n Opmaerksomheden og koncentrationsevnen bliver svaekket, traethedssymptomer begynder, ligesom balance- og bevaegelsesevnen nedsaette.";
}   
    else if ( 1.5 <= ( j / d ) <= 2.0 ) {
    cout<<"\n Svaert forringet bevaegelsesevne og talebesv&#230;r. Centralnervesystemet og maven har faaet nok.";
}   
    else if ( 2.0 <= ( j / d ) <= 3.0 ) {
    cout<<"\n Store forgiftningssymptomer. Selvkontrollen er helt vaek.";
}   
    else if ( 3.0 <= ( j / d ) <= 4.0 ) {
    cout<<"\n Manglende kontrol over f.eks. urinblaeren, evt. bevidstloeshed.";
}   
    else if ( 4.0 <= ( j / d ) <= 100000 ) {
    cout<<"\n Bevidstloeshed, livsfare";
}

    else {
    cout<<"Du er ikke paavirket af alkohol";
	cin.get();
}
cin.get();
}

Thx again !

Tags Taga Tags!`

Take a look at my first post. You shouldn't need to use Globals in your example!

EDIT - why did you put them back as variables?
EDIT2- Perhaps it would be more readable if you made another variable which holds the value of j/d.

try it with some

Code:

if ( j/d>=0.2 $$ j/d<= 0.5 )

instead. What does this program do?