Navarr Barnier: C++, I learned it

Friday, October 2, 2009

C++, I learned it

Practically overnight, too. Of course, that thanks to my knowledge
of Java and PHP, as well as href="http://cplus.about.com/od/learning1/Learn_about_C_and_how_to_write_Programs_in_It.htm">tutorials by
About.com. Basically, C++ is like this:

 1:
            #include <stdio.h>

 2: #include <iostream>

 3: int main(void)

 4: {

 5: // Program statements here.

 6: std::cout <<
            "Hello World" << std::endl;

 7: return 0;

It
all starts with a single function, but you can have such things as classes, overload, etc.
Variables have to be created specifically (int, double, string, float, etc.) before being used, like Java
(unlike PHP) and you have classes that are similar to both Java and PHP, for example:

style="border-bottom: silver 1px solid; text-align: left; border-left: silver 1px solid; padding-bottom:
4px; line-height: 12pt; background-color: #f4f4f4; margin: 20px 0px 10px; padding-left: 4px; width: 97.5%;
padding-right: 4px; font-family: 'Courier New', courier, monospace; direction: ltr;
max-height: 200px; font-size: 8pt; overflow: auto; border-top: silver 1px solid; cursor: text; border-right:
silver 1px solid; padding-top: 4px" id="codeSnippetWrapper">
style="border-bottom-style: none; text-align: left; padding-bottom: 0px; line-height: 12pt;
border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px;
font-family: 'Courier New', courier, monospace; direction: ltr; border-top-style: none;
color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px" id="codeSnippet">

 1: class Polygon

 3: protected:

style="border-bottom-style: none; text-align: left; padding-bottom: 0px; line-height: 12pt;
border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%;
padding-right: 0px; font-family: 'Courier New', courier, monospace; direction: ltr;
border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible;
padding-top: 0px"> 4: int sideAmount;

style="border-bottom-style: none; text-align: left; padding-bottom: 0px; line-height: 12pt;
border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%;
padding-right: 0px; font-family: 'Courier New', courier, monospace; direction: ltr;
border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible;
padding-top: 0px"> 5: double sides[MAX_POLYGON_SIDES];

 6: public:

style="border-bottom-style: none; text-align: left; padding-bottom: 0px; line-height: 12pt;
border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%;
padding-right: 0px; font-family: 'Courier New', courier, monospace; direction: ltr;
border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible;
padding-top: 0px"> 7: bool regular;

style="border-bottom-style: none; text-align: left; padding-bottom: 0px; line-height: 12pt;
border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%;
padding-right: 0px; font-family: 'Courier New', courier, monospace; direction: ltr;
border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible;
padding-top: 0px"> 8: Polygon( style="color: #0000ff">void)

 9: {

 10: regular = false;

 11: }

 12: void setSides(int newSides)

 13: {

 14: sideAmount = newSides;

 15: }

 16: int getSides(void)

 17: {

 18: return sideAmount;

 19: }

 20: int addSide(void)

 21: {

 22: sideAmount += 1;

 23: return getSides();

 24: }

 25: int addSide(int sideValue)

 26: {

 27: sideAmount += 1;

 28:
            setSide(getSides(),sideValue);

 30: }

 31: int addSides(int addAmount)

 32: {

 33: sideAmount +=
            addAmount;

 34:
            return getSides();

 35: }

 36: void setSide(int side,            style="color: #0000ff">double value)

 37: {

 38: side -= 1;

 39: sides[side] = value;

 40: }

 41: double getSide(int side)

 42: {

 43: side -= 1;

 44: return sides[side];

 45: }

 46: double getPerimeter()

 47: {

 48: if(getSides() < 3) { throw
            1; }

 49:
            double total = 0;

 50: for(int i = 1;i <=
            getSides();i++)

 52: total += getSide(i);

 53: }

 54: return total;

 56: };

See?
Does it look that hard? I didn’t think so. And, to help those who haven’t used Java:

 1: #include <stdio.h>

 2: #include <iostream>

 3: #include "Polygon.h"

4:

 5: int main(void)

 6: {

 7: Polygon poly;

 8: poly.setSides(3);

 9: poly.setSide(1,1);

 10: poly.setSide(2,1);

 11: poly.setSide(3,1);

 12: std::cout <<
            "Perimeter: " <<
            poly.getPerimeter() << std::endl;

 13: return 0;

(Will,
of course, return 3).

2 comments:

SMOctober 2, 2009 at 11:06 AM
I have the implementation of polygon area somewhere
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Navarr BarnierAugust 16, 2010 at 7:28 AM
I didn't want to code a function for area because i left it open for irregular
polygons. I'm not mathematically inclined to know if the area for a regular polygon and an irregular
polygone is the same if all the sides are the same length.
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