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Hey there, we were using this [https://www.tutorialspoint.com/compile_cpp_online.php online compiler] to learn some basics about c++. Here are the code snippets we discussed: | |||
Little intro to data types: | Little intro to data types: | ||
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point1.print(); | point1.print(); | ||
point2.print(); | point2.print(); | ||
// this is an array of integers | |||
int integerArray[5] = { 0,1,2,3,4 }; | int integerArray[5] = { 0,1,2,3,4 }; | ||
cout << "first element: " << integerArray[0] << endl; | cout << "first element: " << integerArray[0] << endl; | ||
// we can also declare an array points | |||
Point2D pointArray[3] = {point1, point2, point3 }; | Point2D pointArray[3] = {point1, point2, point3 }; | ||
pointArray[2].print(); | pointArray[2].print(); | ||
// pointer version of the code | // pointer version of the code | ||
Point2D* p2d1_ptr = new Point2D(123, 234); | Point2D* p2d1_ptr = new Point2D(123, 234); |
Latest revision as of 10:39, 11 May 2020
Hey there, we were using this online compiler to learn some basics about c++. Here are the code snippets we discussed:
Little intro to data types:
#include <iostream> #include <string> using namespace std; int main() { int int_number = 2147483647; // 2^32 / 2 -1 = 2^31 -1 = 2147483648 -1 // -2^31 = -2147483648 long long_integer = 9223372036854775807; // 2^64 / 2 - 1= 2^63 -1 = 2147483648 -1 // -2^63 = -2147483648 float low_precision_big_float_number = 9223372036854775807; // 9.22337e+18 = 9.22337 *10^18 double high_precision_big_float_number = 9223372036854775807; // 9.22337e+18 = 9.22337 *10^18 //char are 8bit = 2^8 = 256 char letter_exclamation = 33; // this gets converted through ASCII table to the letter '!' char letter_A = 65; // this gets converted through ASCII table to the letter '!' string text = "this is a string, it's not included by default"; int converted_float = 3.21; cout << "Integer: " << int_number << endl; cout << "Long Integer: " << long_integer << endl; cout << "Overflow Integer: " << int_number + 1 << endl; cout << "Overflow Long Integer: " << long_integer +1 << endl; cout << "Low precision Big float: " << low_precision_big_float_number << endl; cout << "High precision Big float: " << high_precision_big_float_number << endl; // command line is the bottleneck of putting out more precision cout << "Thats the letter '!': " << letter_exclamation << endl; cout << "Thats the letter 'A': " << letter_A << endl; cout << text; return 0; }
The code about classes and pointers:
#include <iostream> using namespace std; class Point2D { public: Point2D(float newX, float newY){ _x = newX; _y = newY; }; float getX() { return _x; }; float getY() { return _y; }; void print() { cout << "(" << getX() << ", " << getY()<< ")" << endl; } private: float _x; float _y; }; int main() { Point2D point1(5,1); Point2D point2(10,100); Point2D point3(27,2); point1.print(); point2.print(); // this is an array of integers int integerArray[5] = { 0,1,2,3,4 }; cout << "first element: " << integerArray[0] << endl; // we can also declare an array points Point2D pointArray[3] = {point1, point2, point3 }; pointArray[2].print(); // pointer version of the code Point2D* p2d1_ptr = new Point2D(123, 234); Point2D* p2d2_ptr = new Point2D(123, 234); Point2D* p2d3_ptr = new Point2D(123, 234); (*p2d1_ptr).print(); p2d1_ptr->print(); Point2D* point_ptr_Array[3] = {p2d1_ptr, p2d2_ptr, p2d3_ptr }; cout << "pointer address: " << point_ptr_Array[0] << "x component of the point at that address: " << point_ptr_Array[0]->getX() << endl; return 0; }