C + +: overview

1. Basic input and output, using cin>> input input, using cout<< output

#include <iostream>using namespacestd;intMain () {inta,b,d,min; cout<<"Enter The numbers:"<<Endl; CIN>>a>>b; cout<<"min ="<< (min=a>b?b:a);  for(d=2;d <min;d++)    if((a%d) = =0) && ((b%d) = =0)) Break; if(d==min) {cout<<"no common denominators"<<Endl; return 0; } cout<<"The lowest common denominator is"<<d<<Endl; return 0;} 

Enter The numbers: 1 2  10

2. Using a reference, the reference is represented by the address symbol &, the reference is another alias to the variable or constant, or the same data

Reference as return value

/*Requirements: Return function values using references*/#include<iostream>using namespacestd;int&f (int&i)//The definition function returns a reference to an integer type equivalent to the return value I{i+=Ten; returni;} intMain () {intk=0; int&m=f (k);//k=i=10cout<<k<<Endl; M= -; cout<<k<<Endl; return 0;}

Ten  -  0

References as parameters

/*Requirement: Reference as function parameter*/#include<iostream>using namespacestd;voidFint&m,intN) { inttemp; temp.=m; M=N; n=temp;}intMain () {intA =5, B =Ten; cout<<"A ="<<a<<" "<<"B ="<<b<<Endl; F (A, b); cout<<"A ="<<a<<" "<<"B ="<<b<<Endl;return 0;} 

5 Ten   ten 0

3. Using the scope Operator::, a function variable or a valid region of a constant or function

/*Requirements: Scope operators::*/#include<iostream>using namespacestd;intI= the;intMain () {inti; I= -;:: I= i+1; cout<<i<<Endl; cout<<::i<<Endl;return 0; }

 - 101  0

4. Simple use of structs, which have their own attribute members and method members, need to create struct member variables to invoke their own properties and methods

//#include <iostream>//#include <cmath>//using namespace std;#include <iostream.h>#include<math.h>structComplex//declares a struct named complex{ DoubleReal//data members, real parts of complex numbers DoubleImag//data members, imaginary parts of complex numbers voidInitDoubleRDoubleI//member function init, assigning the initial value to real and imag{Real=R; Imag=i;} DoubleAbscomplex ()//member function to find the absolute value of a complex number {  DoubleT; T= real*real+imag*Imag; returnsqrt (t);}}; intMain () {Complex A; //defines the member variable A of the structure body complexA.init (1.1,2.2);//Call member function init, assign the initial value to real and imagcout<<"the absolute value of a complex number is:"<<a.abscomplex () <<endl;//Call member function Abscomplex  return 0; }

The absolute value of the complex number is:2.459670

C + +: overview