C + + Reference

• Reference
  • --& Reference character
  • The reference must be initialized
  • Once initialized, it will not change its point to
• Use
  • As a function parameter--does not take up extra space, can improve the function execution efficiency

    • #include <iostream>usingStd::endl;usingstd::cout;//reference functions as parametersvoidSwapintAintb//parameters are passed in the same way that the value is passed--and the copy is{//initial taxiing parameter: int a = x;int B = y;    inttemp =A; A=b; b=temp;}//x/Y values are not exchanged//address Passing-value passingvoidSwaq (int*PA,int*pb) {    inttemp = *PA; *PA = *PB; *PB =temp;}//Address Delivery//Reference Delivery//Benefits: No extra space to increase execution efficiencyvoidSwal (int& Ref1,int&Ref2) {//Parameter initialization: int & ref1 = a;int & ref2 = b;    inttemp =ref1; REF1=Ref2; Ref2=temp;}intMain () {intx =Ten; inty = -; cout<<"x ="<< x <<Endl; cout<<"y ="<< y <<Endl; Swap (x, y);//actual Parameterscout <<"after the Exchange"<<Endl; cout<<"x ="<< x<<Endl; cout<<"y ="<<y<<Endl; Swaq (&x,&y);//actual Parameterscout <<"after the Exchange"<<Endl; cout<<"x ="<< x <<Endl; cout<<"y ="<< y <<Endl; Swal (x, y);//actual Parameterscout <<"after the Exchange"<<Endl; cout<<"x ="<<x<<Endl; cout<<"y ="<<y<<Endl; System ("Pause"); return 0;}

      • Reference can be used as the return value of a function
        • • When the return statement is not copied, it returns the variable itself

          • #include <iostream>usingStd::endl;usingstd::cout;intarr[5] = {0,1,2,3,4 };int& Func (intidx) {    returnarr[idx];}intMain () {func (0) =Ten; cout<< arr[0] <<Endl; System ("Pause"); return 0;}

C + + Reference