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POComparing variables in two instances of a class
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copied!<p>i have what i hope is a quick question about some code i am building out.. basically i want to compare the variables amongst two instances of a class (goldfish) to see if one is inside the territory of another. they both have territory clases which in turn use a point clase made up of an x and y data-point.</p> <p>now i was curious to know why the below doesnt work please:</p> <p>(this bit of code compares two points: a & b, each with two points, a north-east (ne) and south-west (sw) and their x and y plots) if ((a->x_ne <= b->x_ne && a->y_ne <= b-> ne) && (a->x_sw => b->x_sw && a->y_sw => b-> sw)) { return true; } else return false;</p> <p>I can think of a work around (for instance, by having a get location method), and using a function in the main body to compare, but im curious to know --as a budding c++ programmer -- why the above, or a similar implementation doesnt appear to work.</p> <p>and also, what would be the CLEANEST and most elegant way to accomplish the above? have a friend function perhaps?</p> <p>many thanks </p> <p>edit: added some comments to (hopefully make the variables clearer)</p> <pre><code>// class point { // public: // float x; // float y; // point(float x_in, float y_in) { //the 2 arg constructor // x = x_in; // y = y_in; // } // }; // class territory { // private: // point ne, sw; // public: // territory(float x_ne, float y_ne, float x_sw, float y_sw) // : ne(x_ne, y_ne), sw(x_sw,y_sw) { // } // bool contain_check(territory a, territory b) { // //checks if a is contained in b (in THAT order!) // if ((a->x_ne <= b->x_ne && a->y_ne <= b-> ne) && // (a->x_sw => b->x_sw && a->y_sw => b-> sw)) { // return true; // } else return false; </code></pre> <p>^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^</p> <pre><code>// }; // class goldfish { // protected: // float size; // point pos; // territory terr; // public: // goldfish(float x, float y) : pos(x,y), terr(x-1,y-1,x+1,y+1) { //constructor // size = 2.3; // } // void retreat() { //what happens in the case of loss in attack // /* // if(goldfish.size[1] - goldfish.size[2] <= 1 && goldfish.size[1] - goldfish.size[2] > 0) { // size = size - 0.2; // } // */ // } // void triumph() { // } // void attack() { // } // // void goldfish() // }; </code></pre>

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