C++ 更多特性

1、類(lèi)變量必須在classclass聲明的外聲明的外面單獨(dú)聲明面單獨(dú)聲明，并初始化。如果不初始化，則編譯器自動(dòng)初始化0int Counter:cnt;或int Counter:cnt = 0;A o2 = o1;使用copy constructorA o2;o2 = o1;使用賦值語(yǔ)句V a(3);V a(3);V b = a;V b = a;.* *b.pvb.pv=100;=100;a.dispa.disp( );( );b.dispb.disp( );( );V(const V& s) V(const V& s) pvpv = new int; = new int;* *pv = pv =

2、* *s.pvs.pv; ; V a(3);V a(3);V b(5);V b(5);b = a;b = a;a.dispa.disp( );( );b.dispb.disp( );( );Pixel p1(1, 2);Pixel p1(1, 2);Pixel p2(3, 5, 1);Pixel p2(3, 5, 1);p2 = p1;p2 = p1;p1.draw( );p1.draw( );p2.draw( );p2.draw( );Class Pixel Class Pixel Public:Public: Pixel& operator=(const Pixel& s) Pixel&

3、operator=(const Pixel& s) x = s.y; y = s.x; color x = s.y; y = s.x; color = !s.color;= !s.color; ;A o;A o;直接調(diào)用直接調(diào)用constructorconstructor，構(gòu)造對(duì)象，構(gòu)造對(duì)象o oA o;A o;o = A( );o = A( );直接調(diào)用直接調(diào)用constructor constructor ，構(gòu)造對(duì)象，構(gòu)造對(duì)象o o再構(gòu)造出一個(gè)臨時(shí)對(duì)象，并將該臨再構(gòu)造出一個(gè)臨時(shí)對(duì)象，并將該臨時(shí)對(duì)象賦給時(shí)對(duì)象賦給o o， (operator= is (operator= is called)

4、called)A o1;A o1;A o2 = o1;A o2 = o1;直接調(diào)用直接調(diào)用constructor constructor ，構(gòu)造對(duì)象，構(gòu)造對(duì)象o1o1用用o1o1作參數(shù)，再調(diào)用作參數(shù)，再調(diào)用copy copy constructorconstructor構(gòu)造對(duì)象構(gòu)造對(duì)象o2o2class A class A int a,b;int a,b;public:public:A(intA(int x, int y) : a(x), x, int y) : a(x), b(y) b(y) A& operator + ( );A& operator + ( );A operator+ (int );/A operator+ (int );/后后+;A A:operator+(intA A:operator+(int dummy) dummy) A