Squaring numbers in c++

Sanka792 · 01-27-2009, 12:13 PM

hey people!
I am trying to make a calculator in C++.
I am stuck on how to square a number.
Would anybody know how to do this?

**laserlight** · 01-27-2009, 12:17 PM

You er... multiply the number by itself.

Sanka792 · 01-27-2009, 12:20 PM

Quote:

Originally Posted by laserlight

You er... multiply the number by itself.

oke and how do you square root a number?

**laserlight** · 01-27-2009, 12:23 PM

Quote:

Originally Posted by Sanka792

oke and how do you square root a number?

That depends on how you want to do it, but one way is to use the std::sqrt function from <cmath>. That said, it would be wiser to start by implementing say, addition, and only implement other functionality after you have a working prototype.

iMalc · 01-27-2009, 12:29 PM

Google is your friend

Sanka792 · 01-27-2009, 12:31 PM

Quote:

Originally Posted by laserlight

You er... multiply the number by itself.

Quote:

Originally Posted by laserlight

That depends on how you want to do it, but one way is to use the std::sqrt function from <cmath>. That said, it would be wiser to start by implementing say, addition, and only implement other functionality oafter you have a working prototype.

coudl you give an example of using this function. For example how to find the square root of 16?

**laserlight** · 01-27-2009, 12:33 PM

Quote:

Originally Posted by Sanka792

coudl you give an example of using this function. For example how to find the square root of 16?

You could read say, cppreference.com's entry on sqrt, and/or you could search the Web as iMalc suggested.

anon · 01-27-2009, 12:34 PM

Um, it takes a value (16) and returns the square root of the value (4.0). There's nothing more to it. Do you have an idea how to call any function?

Kudose · 01-27-2009, 12:34 PM

Code:

#include <iostream>
#include <cmath>

int main(){
  int n = 16; // number to square root
  std::cout << std::sqrt(n) << std::endl;
}

This was not compiled and just getting the answer doesn't do you any good.

legit · 01-27-2009, 12:35 PM

Quote:

Originally Posted by Sanka792

coudl you give an example of using this function. For example how to find the square root of 16?

Well from where i'm sitting, it sounds like a big function to me. I havn't made a calc persae, but i'll probably make one now just for the fun of it. The way I would do it would be trial and error. Think about the behaviour of numbers. An odd number multiplied by an odd number is obviously going to be an odd number. Start from there, create a method of finding out if the input number was even or odd, then take it from there.

Sanka792 · 01-27-2009, 12:40 PM

Thnks guys so much for the help.
I now know what to do.
I already have a prototype that can add, subtract, multiply and divide.
But i was thinking of adding in formulas like the -b formula.

But i goit another question.
Is it possible to create an interface for c++ so that it looks like a program?
I mean a console that a user can use that covers up command prompt?

legit · 01-27-2009, 12:43 PM

Quote:

Originally Posted by Sanka792

Thnks guys so much for the help.
I now know what to do.
I already have a prototype that can add, subtract, multiply and divide.
But i was thinking of adding in formulas like the -b formula.

But i goit another question.
Is it possible to create an interface for c++ so that it looks like a program?
I mean a console that a user can use that covers up command prompt?

You mean like a Window? This is called a GUI(Graphical User Interface). Yes this is possible, but hard work. I myself cannot get the hang of it, although poeple on the boards will gladly help you.

**laserlight** · 01-27-2009, 12:46 PM

Quote:

Originally Posted by Sanka792

Is it possible to create an interface for c++ so that it looks like a program?
I mean a console that a user can use that covers up command prompt?

As in a graphical user interface that say, resembles a hand held calculator? Yes, but since you appear relatively new to C++... not yet.

At the moment I would suggest a "classical" problem: allow the user to enter an arithmetic expression, from the console window, in reverse Polish notation (search the Web if you must). When you are satisfied with what you have done, allow the user to enter an arithmetic expression in the "normal" infix notation. You could always reuse this later on when you do write a GUI calculator.

dwks · 01-27-2009, 02:03 PM

Just a note: if you wanted to raise a number to an arbitrary power, you can use the pow() function, also in <cmath>.

01-27-2009, 12:13 PM	#1
Sanka792 Registered User Join Date: Jan 2009 Posts: 4	Squaring numbers in c++ hey people! I am trying to make a calculator in C++. I am stuck on how to square a number. Would anybody know how to do this?
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01-27-2009, 12:17 PM	#2
laserlight C++ Witch Join Date: Oct 2003 Location: Singapore Posts: 11,372	You er... multiply the number by itself. __________________ C + C++ Compiler: MinGW port of GCC Build + Version Control System: SCons + Bazaar Look up a C/C++ Reference and learn How To Ask Questions The Smart Way
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01-27-2009, 12:29 PM	#5
iMalc Algorithm Dissector Join Date: Dec 2005 Location: New Zealand Posts: 2,744	Google is your friend __________________ My homepage Advice: Take only as directed - If symptoms persist, please see your debugger
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01-27-2009, 12:34 PM	#9
Kudose Registered User Join Date: Jun 2006 Posts: 83	Code: #include <iostream> #include <cmath> int main(){ int n = 16; // number to square root std::cout << std::sqrt(n) << std::endl; } This was not compiled and just getting the answer doesn't do you any good.
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01-27-2009, 12:40 PM	#11
Sanka792 Registered User Join Date: Jan 2009 Posts: 4	Thnks guys so much for the help. I now know what to do. I already have a prototype that can add, subtract, multiply and divide. But i was thinking of adding in formulas like the -b formula. But i goit another question. Is it possible to create an interface for c++ so that it looks like a program? I mean a console that a user can use that covers up command prompt?
Sanka792 is offline

01-27-2009, 02:03 PM	#14
dwks Frequently Quite Prolix Join Date: Apr 2005 Location: Canada Posts: 7,698	Just a note: if you wanted to raise a number to an arbitrary power, you can use the pow() function, also in <cmath>. __________________ dwk Seek and ye shall find. quaere et invenies. "Simplicity does not precede complexity, but follows it." -- Alan Perlis "Testing can only prove the presence of bugs, not their absence." -- Edsger Dijkstra "The only real mistake is the one from which we learn nothing." -- John Powell Other boards: DaniWeb, TPS Unofficial Wiki FAQ: cpwiki.sf.net My website: http://dwks.theprogrammingsite.com/ Projects: codeform, xuni, atlantis, nort, etc.
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