learning C++

[N-Aldwitch]

Goto is greatly discouraged in the programming community and it's very, very bad to use when you're programming with others and working for someone.

[fishfin]

That was just what I was looking for, thanks.

I probably didn't explane very well what I wanted to do, I want to be able to go back and start running code from line 20 when I get line 100 kind of like it does lots of things (lines 1-99) but on line 100 there is some code telling it to go back to line 20 so it runs code line 20-99 but on line 100 there is some code telling it to go back to line 20 so it runs code line 20-99 but on line 100 there is some code telling it to go back to line 20 so it runs code line 20-99 but on line 100 there is some code telling it to go back to line 20 so it runs code line 20-99 but on line 100 there is some code telling it to go back to line 20 so it runs code line 20-99 but on line 100 there is some code telling it to go back to line 20 so it runs code line 20-99...

And how do you make 'x' something other than a number?

http://www.cprogramming.com/tutorial/lesson3.html

http://www.cprogramming.com/tutorial/lesson4.html

I had read that but didn't understand enugh to do anything with it.

[N-Aldwitch]

I prefer php over C++ in general. Learn PHP first...

[Peanut]

I prefer php over C++ in general. Learn PHP first...

Huh?

That's one of the weirdest statements I've ever heard.

Not only that C++ and php aren't related in the most commen way.

Ie it's like comparing webpages to standalone programs.

[west]

Maybe he means CSS?

/me is learning xhtml and css, finally.

[fishfin]

I have another question...
When I first started learning C++ I wrote a calculator in it just to practice.
A few days ago I decided to try to add a square root function to it but I can't seem to get it to work.

cout<<"Enter the first number:";
cin>> number1;
cin.ignore();
number1 = answer * answer;
cout<<"The square root of "<<number1 <<" is "<<answer <<".";

cout<<"Enter the first number:";
cin>> number1;
cin.ignore();
number1 = number2 * answer;
number2 = anwer;
cout<<"The square root of "<<number1 <<" is "<<answer <<".";

I tried both of those, maybe I'm just doing something wrong?

[Lord_Igor]

Yes, you are doing it wrong.

Code: Select all

number1 = answer * answer;

This will give number1 the value of answer times itself. The earlier inputted value is lost. The value of answer is most likely not what you want it to be. I am assuming you declared both variables earlier or else it won't compile.

Code: Select all

number1 = number2 * answer;
number2 = anwer;

I will first ignore you're typo. The first line will give number1 the value of number2 times answer. The inputted value is lost here also. The second line will then give number2 the value of answer.

What you want to do is use the function sqrt(). It will return the square root of the number given as argument. You must include the math library.

Code: Select all

cout<<"Enter the first number:";
cin>> number1;
cin.ignore();
answer = sqrt(number1);
cout<<"The square root of "<<number1 <<" is "<<answer <<".";

[fishfin]

I tried:

cout<<"Enter the first number:";
cin>> number1;
cin.ignore();
answer = sqrt(number1);
cout<<"The square root of "<<number1 <<" is "<<answer <<".";

but I got an error saying:

'sqrt' undeclared (first use this function)

I use Dev-C++.[/quote]

[Lord_Igor]

Did you include math.h?

[fishfin]

no, I'll try that.

[Birdsall007]

How's it going? Did you get the looping to work?

[fishfin]

no, I haven't goten the looping to work (I haven't tried very hard either), but the square root works (thanks for the help).

[fishfin]

I've figured out how to make loops!!

but I still haven't figured out how to check to see if a word has been entered (I couldn't think of a better way to describe it)

Here is what I've been trying:

#include <iostream>
#include <string>

using namespace std;

int main()
{
char pass;

cout<<"enter password:";
cin>> pass;
cin.ignore();

if ( pass == password ) {
cout<<"correct!";
cin.get();
}
}

I get this warning saying: 'password' undeclared (first use this function)

[Lord_Igor]

I get this warning saying: 'password' undeclared (first use this function)

As it says, you need to declare password. E.g.

Code: Select all

char password;

Though, the way you have it written now the password will only be one character long. Also you need to give password a value. I suggest either declaring pass and password like

Code: Select all

char pass[20];
char password[20] = "fishfinisbest";

and then use strcmp(), include string.h,

Code: Select all

if (strcmp(pass,password)==0) {...}

or you could use String

Code: Select all

String pass;
String password = "fishfinisbest";
...
if (pass == password) {...}

[fishfin]

I did this:

#include <iostream>
#include <string>

using namespace std;

int main()
{
char pass1[8], pass2[8] = "password";

cout<<"enter password:";
cin>> pass1;
cin.ignore();

if ( strcmp ( pass1, pass2 ) == 0 ) {
cout<<"correct!";
cin.get();
}
}

and I got a warning saying: initializer-string for array of chars is to long