{"id":355,"date":"2020-11-03T11:22:28","date_gmt":"2020-11-03T15:22:28","guid":{"rendered":"http:\/\/www.prglab.com\/blog\/?page_id=355"},"modified":"2020-11-03T11:22:28","modified_gmt":"2020-11-03T15:22:28","slug":"overloading-operators","status":"publish","type":"page","link":"https:\/\/www.prglab.com\/blog\/cplusplus-tutorial\/object-oriented\/overloading-operators","title":{"rendered":"\u64cd\u4f5c\u7b26\u91cd\u8f7d"},"content":{"rendered":"\n

4.2 \u64cd\u4f5c\u7b26\u91cd\u8f7d\uff08Overloading operators\uff09<\/h2>\n\n\n\n

C++ \u5b9e\u73b0\u4e86\u5728\u7c7b(class)\u4e4b\u95f4\u4f7f\u7528\u8bed\u8a00\u6807\u51c6\u64cd\u4f5c\u7b26\uff0c\u800c\u4e0d\u53ea\u662f\u5728\u57fa\u672c\u6570\u636e\u7c7b\u578b\u4e4b\u95f4\u4f7f\u7528\u3002\u4f8b\u5982\uff1aint a, b, c;
a = b + c;<\/code><\/p>\n\n\n\n

\u662f\u6709\u6548\u64cd\u4f5c\uff0c\u56e0\u4e3a\u52a0\u53f7\u4e24\u8fb9\u7684\u53d8\u91cf\u90fd\u662f\u57fa\u672c\u6570\u636e\u7c7b\u578b\u3002\u7136\u800c\uff0c\u6211\u4eec\u662f\u5426\u53ef\u4ee5\u8fdb\u884c\u4e0b\u9762\u7684\u64cd\u4f5c\u5c31\u4e0d\u662f\u90a3\u4e48\u663e\u800c\u6613\u89c1\u4e86\uff08\u5b83\u5b9e\u9645\u4e0a\u662f\u6b63\u786e\u7684\uff09\uff1astruct { char product [50]; float price; } a, b, c;
a = b + c;<\/code><\/p>\n\n\n\n

\u5c06\u4e00\u4e2a\u7c7bclass (\u6216\u7ed3\u6784struct)\u7684\u5bf9\u8c61\u8d4b\u7ed9\u53e6\u4e00\u4e2a\u540c\u79cd\u7c7b\u578b\u7684\u5bf9\u8c61\u662f\u5141\u8bb8\u7684(\u901a\u8fc7\u4f7f\u7528\u9ed8\u8ba4\u7684\u590d\u5236\u6784\u9020\u51fd\u6570 copy constructor)\u3002\u4f46\u76f8\u52a0\u64cd\u4f5c\u5c31\u6709\u53ef\u80fd\u4ea7\u751f\u9519\u8bef\uff0c\u7406\u8bba\u4e0a\u8bb2\u5b83\u5728\u975e\u57fa\u672c\u6570\u636e\u7c7b\u578b\u4e4b\u95f4\u662f\u65e0\u6548\u7684\u3002<\/p>\n\n\n\n

\u4f46\u5f52\u529f\u4e8eC++ \u7684\u64cd\u4f5c\u7b26\u91cd\u8f7d\uff08overload\uff09\u80fd\u529b\uff0c\u6211\u4eec\u53ef\u4ee5\u5b8c\u6210\u8fd9\u4e2a\u64cd\u4f5c\u3002\u50cf\u4ee5\u4e0a\u4f8b\u5b50\u4e2d\u8fd9\u6837\u7684\u7ec4\u5408\u7c7b\u578b\u7684\u5bf9\u8c61\u5728C++\u4e2d\u53ef\u4ee5\u63a5\u53d7\u5982\u679c\u6ca1\u6709\u64cd\u4f5c\u7b26\u91cd\u8f7d\u5219\u4e0d\u80fd\u88ab\u63a5\u53d7\u7684\u64cd\u4f5c\uff0c\u6211\u4eec\u751a\u81f3\u53ef\u4ee5\u4fee\u6539\u8fd9\u4e9b\u64cd\u4f5c\u7b26\u7684\u6548\u679c\u3002\u4ee5\u4e0b\u662f\u6240\u6709\u53ef\u4ee5\u88ab\u91cd\u8f7d\u7684\u64cd\u4f5c\u7b26\u7684\u5217\u8868\uff1a<\/p>\n\n\n\n

\t+    -    *    \/    =    <    >    +=   -=   *=   \/=   <<   >>
\t<<=  >>=  ==   !=   <=   >=   ++   --   %    &    ^    !    |
\t~    &=   ^=   |=   &&   ||   %=   []   ()   new  delete
\t<\/pre>\n\n\n\n
\u8981\u60f3\u91cd\u8f7d\u4e00\u4e2a\u64cd\u4f5c\u7b26\uff0c\u6211\u4eec\u53ea\u9700\u8981\u7f16\u5199\u4e00\u4e2a\u6210\u5458\u51fd\u6570\uff0c\u540d\u4e3aoperator \uff0c\u540e\u9762\u8ddf\u6211\u4eec\u8981\u91cd\u8f7d\u7684\u64cd\u4f5c\u7b26\uff0c\u9075\u5faa\u4ee5\u4e0b\u539f\u578b\u5b9a\u4e49\uff1atype operator sign (parameters);<\/code><\/p>\n\n\n\n
\u8fd9\u91cc\u662f\u4e00\u4e2a\u64cd\u4f5c\u7b26 +\u7684\u4f8b\u5b50\u3002\u6211\u4eec\u8981\u8ba1\u7b97\u4e8c\u7ef4\u5411\u91cf(bidimensional vector) a(3,1) \u4e0eb(1,2)\u7684\u548c\u3002\u4e24\u4e2a\u4e8c\u7ef4\u5411\u91cf\u76f8\u52a0\u7684\u64cd\u4f5c\u5f88\u7b80\u5355\uff0c\u5c31\u662f\u5c06\u4e24\u4e2ax \u8f74\u7684\u503c\u76f8\u52a0\u83b7\u5f97\u7ed3\u679c\u7684x \u8f74\u503c\uff0c\u5c06\u4e24\u4e2a y \u8f74\u503c\u76f8\u52a0\u83b7\u5f97\u7ed3\u679c\u7684 y\u503c\u3002\u5728\u8fd9\u4e2a\u4f8b\u5b50\u91cc\uff0c\u7ed3\u679c\u662f (3+1,1+2) = (4,3)\u3002<\/p>\n\n\n\n
\/\/ vectors: overloading operators example #include <iostream.h> class CVector { public: int x,y; CVector () {}; CVector (int,int); CVector operator + (CVector); }; CVector::CVector (int a, int b) { x = a; y = b; } CVector CVector::operator+ (CVector param) { CVector temp; temp.x = x + param.x; temp.y = y + param.y; return (temp); } int main () { CVector a (3,1); CVector b (1,2); CVector c; c = a + b; cout << c.x << “,” << c.y; return 0; }<\/td>4,3

<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\u5982\u679c\u4f60\u8ff7\u60d1\u4e3a\u4ec0\u4e48\u770b\u5230\u8fd9\u4e48\u591a\u904d\u7684 CVector\uff0c\u90a3\u662f\u56e0\u4e3a\u5176\u4e2d\u6709\u4e9b\u662f\u6307class\u540d\u79f0CVector \uff0c\u800c\u53e6\u4e00\u4e9b\u662f\u4ee5\u5b83\u547d\u540d\u7684\u51fd\u6570\u540d\u79f0\uff0c\u4e0d\u8981\u628a\u5b83\u4eec\u641e\u6df7\u4e86\uff1a CVector (int, int); \/\/ \u51fd\u6570\u540d\u79f0 CVector (constructor) CVector operator+ (CVector); \/\/ \u51fd\u6570 operator+ \u8fd4\u56deCVector \u7c7b\u578b\u7684\u503c Class CVector\u7684\u51fd\u6570 operator+ \u662f\u5bf9\u6570\u5b66\u64cd\u4f5c\u7b26+\u8fdb\u884c\u91cd\u8f7d\u7684\u51fd\u6570\u3002\u8fd9\u4e2a\u51fd\u6570\u53ef\u4ee5\u7528\u4ee5\u4e0b\u4e24\u79cd\u65b9\u6cd5\u8fdb\u884c\u8c03\u7528\uff1ac = a + b;
c = a.operator+ (b);\u6ce8\u610f\uff1a<\/strong>\u6211\u4eec\u5728\u8fd9\u4e2a\u4f8b\u5b50\u4e2d\u5305\u62ec\u4e86\u4e00\u4e2a\u7a7a\u6784\u9020\u51fd\u6570 (\u65e0\u53c2\u6570)\uff0c\u800c\u4e14\u6211\u4eec\u5c06\u5b83\u5b9a\u4e49\u4e3a\u65e0\u4efb\u4f55\u64cd\u4f5c\uff1aCVector ( ) { };\u8fd9\u662f\u5f88\u5fc5\u8981\u7684\uff0c\u56e0\u4e3a\u4f8b\u5b50\u4e2d\u5df2\u7ecf\u6709\u53e6\u4e00\u4e2a\u6784\u9020\u51fd\u6570\uff0cCVector (int, int);\u56e0\u6b64\uff0c\u5982\u679c\u6211\u4eec\u4e0d\u50cf\u4e0a\u9762\u8fd9\u6837\u660e\u786e\u5b9a\u4e49\u4e00\u4e2a\u7684\u8bdd\uff0cCVector\u7684\u4e24\u4e2a\u9ed8\u8ba4\u6784\u9020\u51fd\u6570\u90fd\u4e0d\u5b58\u5728\u3002\u8fd9\u6837\u7684\u8bdd\uff0cmain( )\u4e2d\u5305\u542b\u7684\u8bed\u53e5CVector c;\u5c06\u4e3a\u4e0d\u5408\u6cd5\u7684\u3002\u5c3d\u7ba1\u5982\u6b64\uff0c\u6211\u5df2\u7ecf\u8b66\u544a\u8fc7\u4e00\u4e2a\u7a7a\u8bed\u53e5\u5757 (no-op block)\u5e76\u4e0d\u662f\u4e00\u79cd\u503c\u5f97\u63a8\u8350\u7684\u6784\u9020\u51fd\u6570\u7684\u5b9e\u73b0\u65b9\u5f0f\uff0c\u56e0\u4e3a\u5b83\u4e0d\u80fd\u5b9e\u73b0\u4e00\u4e2a\u6784\u9020\u51fd\u6570\u81f3\u5c11\u5e94\u8be5\u5b8c\u6210\u7684\u57fa\u672c\u529f\u80fd\uff0c\u4e5f\u5c31\u662f\u521d\u59cb\u5316class\u4e2d\u7684\u6240\u6709\u53d8\u91cf\u3002\u5728\u6211\u4eec\u7684\u4f8b\u5b50\u4e2d\uff0c\u8fd9\u4e2a\u6784\u9020\u51fd\u6570\u6ca1\u6709\u5b8c\u6210\u5bf9\u53d8\u91cfx \u548c y \u7684\u5b9a\u4e49\u3002\u56e0\u6b64\u4e00\u4e2a\u66f4\u503c\u5f97\u63a8\u8350\u7684\u6784\u9020\u51fd\u6570\u5b9a\u4e49\u5e94\u8be5\u50cf\u4e0b\u9762\u8fd9\u6837\uff1aCVector ( ) { x=0; y=0; };\u5c31\u50cf\u4e00\u4e2aclass\u9ed8\u8ba4\u5305\u542b\u4e00\u4e2a\u7a7a\u6784\u9020\u51fd\u6570\u548c\u4e00\u4e2a\u590d\u5236\u6784\u9020\u51fd\u6570\u4e00\u6837\uff0c\u5b83\u540c\u65f6\u5305\u542b\u4e00\u4e2a\u5bf9\u8d4b\u503c\u64cd\u4f5c\u7b26assignation operator (=)\u7684\u9ed8\u8ba4\u5b9a\u4e49\uff0c\u8be5\u64cd\u4f5c\u7b26\u7528\u4e8e\u4e24\u4e2a\u540c\u7c7b\u5bf9\u8c61\u4e4b\u95f4\u3002\u8fd9\u4e2a\u64cd\u4f5c\u7b26\u5c06\u5176\u53c2\u6570\u5bf9\u8c61(\u7b26\u53f7\u53f3\u8fb9\u7684\u5bf9\u8c61) \u7684\u6240\u6709\u975e\u9759\u6001 (non-static) \u6570\u636e\u6210\u5458\u590d\u5236\u7ed9\u5176\u5de6\u8fb9\u7684\u5bf9\u8c61\u3002\u5f53\u7136\uff0c\u4f60\u4e5f\u53ef\u4ee5\u5c06\u5b83\u91cd\u65b0\u5b9a\u4e49\u4e3a\u4f60\u60f3\u8981\u7684\u4efb\u4f55\u529f\u80fd\uff0c\u4f8b\u5982\uff0c\u53ea\u62f7\u8d1d\u67d0\u4e9b\u7279\u5b9aclass\u6210\u5458\u3002\u91cd\u8f7d\u4e00\u4e2a\u64cd\u4f5c\u7b26\u5e76\u4e0d\u8981\u6c42\u4fdd\u6301\u5176\u5e38\u89c4\u7684\u6570\u5b66\u542b\u4e49\uff0c\u867d\u7136\u8fd9\u662f\u63a8\u8350\u7684\u3002\u4f8b\u5982\uff0c\u867d\u7136\u6211\u4eec\u53ef\u4ee5\u5c06\u64cd\u4f5c\u7b26+\u5b9a\u4e49\u4e3a\u53d6\u4e24\u4e2a\u5bf9\u8c61\u7684\u5dee\u503c\uff0c\u6216\u7528==\u64cd\u4f5c\u7b26\u5c06\u4e00\u4e2a\u5bf9\u8c61\u8d4b\u4e3a0\uff0c\u4f46\u8fd9\u6837\u505a\u662f\u6ca1\u6709\u4ec0\u4e48\u903b\u8f91\u610f\u4e49\u7684\u3002\u867d\u7136\u51fd\u6570operator+ \u7684\u539f\u578b\u5b9a\u4e49\u770b\u8d77\u6765\u5f88\u660e\u663e\uff0c\u56e0\u4e3a\u5b83\u53d6\u64cd\u4f5c\u7b26\u53f3\u8fb9\u7684\u5bf9\u8c61\u4e3a\u5176\u5de6\u8fb9\u5bf9\u8c61\u7684\u51fd\u6570operator+\u7684\u53c2\u6570\uff0c\u5176\u5b83\u7684\u64cd\u4f5c\u7b26\u5c31\u4e0d\u4e00\u5b9a\u8fd9\u4e48\u660e\u663e\u4e86\u3002\u4ee5\u4e0b\u5217\u8868\u603b\u7ed3\u4e86\u4e0d\u540c\u7684\u64cd\u4f5c\u7b26\u51fd\u6570\u662f\u600e\u6837\u5b9a\u4e49\u58f0\u660e\u7684 (\u7528\u64cd\u4f5c\u7b26\u66ff\u6362\u6bcf\u4e2a@):ExpressionOperator (@)Function memberGlobal function@a+ - * & ! ~ ++ --A::operator@( )operator@(A)a@++ --A::operator@(int)operator@(A, int)a@b+ - * \/ % ^ & | < > == != <= >= << >> && || ,A::operator@(B)operator@(A, B)a@b= += -= *= \/= %= ^= &= |= <<= >>= [ ]A::operator@(B)-a(b, c...)( )A::operator()(B, C...)-a->b->A::operator->()-* \u8fd9\u91cca \u662fclass A\u7684\u4e00\u4e2a\u5bf9\u8c61\uff0cb \u662f B \u7684\u4e00\u4e2a\u5bf9\u8c61\uff0cc \u662fclass C \u7684\u4e00\u4e2a\u5bf9\u8c61\u3002\u4ece\u4e0a\u8868\u53ef\u4ee5\u770b\u51fa\u6709\u4e24\u79cd\u65b9\u6cd5\u91cd\u8f7d\u4e00\u4e9bclass\u64cd\u4f5c\u7b26\uff1a\u4f5c\u4e3a\u6210\u5458\u51fd\u6570\uff08member function\uff09\u6216\u4f5c\u4e3a\u5168\u57df\u51fd\u6570(global function)\u3002\u5b83\u4eec\u7684\u7528\u6cd5\u6ca1\u6709\u533a\u522b\uff0c\u4f46\u662f\u6211\u8981\u63d0\u9192\u4f60\uff0c\u5982\u679c\u4e0d\u662fclass\u7684\u6210\u5458\u51fd\u6570\uff0c\u5219\u4e0d\u80fd\u8bbf\u95ee\u8be5class\u7684private \u6216 protected \u6210\u5458\uff0c\u9664\u975e\u8fd9\u4e2a\u5168\u57df\u51fd\u6570\u662f\u8be5class\u7684 friend (friend \u7684\u542b\u4e49\u5c06\u5728\u540e\u9762\u7684\u7ae0\u8282\u89e3\u91ca)\u3002
\u5173\u952e\u5b57 this\u5173\u952e\u5b57this \u901a\u5e38\u88ab\u7528\u5728\u4e00\u4e2aclass\u5185\u90e8\uff0c\u6307\u6b63\u5728\u88ab\u6267\u884c\u7684\u8be5class\u7684\u5bf9\u8c61(object)\u5728\u5185\u5b58\u4e2d\u7684\u5730\u5740\u3002\u5b83\u662f\u4e00\u4e2a\u6307\u9488\uff0c\u5176\u503c\u6c38\u8fdc\u662f\u81ea\u8eabobject\u7684\u5730\u5740\u3002\u5b83\u53ef\u4ee5\u88ab\u7528\u6765\u68c0\u67e5\u4f20\u5165\u4e00\u4e2a\u5bf9\u8c61\u7684\u6210\u5458\u51fd\u6570\u7684\u53c2\u6570\u662f\u5426\u662f\u8be5\u5bf9\u8c61\u672c\u8eab\u3002\u4f8b\u5982\uff1a \/\/ this #include <iostream.h> class CDummy { public: int isitme (CDummy& param); }; int CDummy::isitme (CDummy& param) { if (&param == this) return 1; else return 0; } int main () { CDummy a; CDummy* b = &a; if ( b->isitme(a) ) cout << \"yes, &a is b\"; return 0; } yes, &a is b\u5b83\u8fd8\u7ecf\u5e38\u88ab\u7528\u5728\u6210\u5458\u51fd\u6570operator= \u4e2d\uff0c\u7528\u6765\u8fd4\u56de\u5bf9\u8c61\u7684\u6307\u9488(\u907f\u514d\u4f7f\u7528\u4e34\u65f6\u5bf9\u8c61)\u3002\u4ee5\u4e0b\u7528\u524d\u9762\u770b\u5230\u7684\u5411\u91cf(vector)\u7684\u4f8b\u5b50\u6765\u770b\u4e00\u4e0b\u51fd\u6570operator= \u662f\u600e\u6837\u5b9e\u73b0\u7684\uff1a CVector& CVector::operator= (const CVector& param) {
x=param.x;
y=param.y;
return *this;
}\u5b9e\u9645\u4e0a\uff0c\u5982\u679c\u6211\u4eec\u6ca1\u6709\u5b9a\u4e49\u6210\u5458\u51fd\u6570operator=\uff0c\u7f16\u8bd1\u5668\u81ea\u52a8\u4e3a\u8be5class\u751f\u6210\u7684\u9ed8\u8ba4\u4ee3\u7801\u6709\u53ef\u80fd\u5c31\u662f\u8fd9\u4e2a\u6837\u5b50\u7684\u3002
\u9759\u6001\u6210\u5458(Static members)\u4e00\u4e2aclass \u53ef\u4ee5\u5305\u542b\u9759\u6001\u6210\u5458(static members)\uff0c\u53ef\u4ee5\u662f\u6570\u636e\uff0c\u4e5f\u53ef\u4ee5\u662f\u51fd\u6570\u3002\u4e00\u4e2aclass\u7684\u9759\u6001\u6570\u636e\u6210\u5458\u4e5f\u88ab\u79f0\u4f5c\u7c7b\u53d8\u91cf\"class variables\"\uff0c\u56e0\u4e3a\u5b83\u4eec\u7684\u5185\u5bb9\u4e0d\u4f9d\u8d56\u4e8e\u67d0\u4e2a\u5bf9\u8c61\uff0c\u5bf9\u540c\u4e00\u4e2aclass\u7684\u6240\u6709object\u5177\u6709\u76f8\u540c\u7684\u503c\u3002\u4f8b\u5982\uff0c\u5b83\u53ef\u4ee5\u88ab\u7528\u4f5c\u8ba1\u7b97\u4e00\u4e2aclass\u58f0\u660e\u7684objects\u7684\u4e2a\u6570\uff0c\u89c1\u4ee5\u4e0b\u4ee3\u7801\u7a0b\u5e8f\uff1a \/\/ static members in classes #include <iostream.h> class CDummy { public: static int n; CDummy () { n++; }; ~CDummy () { n--; }; }; int CDummy::n=0; int main () { CDummy a; CDummy b[5]; CDummy * c = new CDummy; cout << a.n << endl; delete c; cout << CDummy::n << endl; return 0; } 7
6\u5b9e\u9645\u4e0a\uff0c\u9759\u6001\u6210\u5458\u4e0e\u5168\u57df\u53d8\u91cf(global variable)\u5177\u6709\u76f8\u540c\u7684\u5c5e\u6027\uff0c\u4f46\u5b83\u4eab\u6709\u7c7b(class)\u7684\u8303\u56f4\u3002\u56e0\u6b64\uff0c\u6839\u636eANSI-C++ \u6807\u51c6\uff0c\u4e3a\u4e86\u907f\u514d\u5b83\u4eec\u88ab\u591a\u6b21\u91cd\u590d\u58f0\u660e\uff0c\u5728class\u7684\u58f0\u660e\u4e2d\u53ea\u80fd\u591f\u5305\u62ecstatic member\u7684\u539f\u578b(\u58f0\u660e)\uff0c\u800c\u4e0d\u80fd\u591f\u5305\u62ec\u5176\u5b9a\u4e49(\u521d\u59cb\u5316\u64cd\u4f5c)\u3002\u4e3a\u4e86\u521d\u59cb\u5316\u4e00\u4e2a\u9759\u6001\u6570\u636e\u6210\u5458\uff0c\u6211\u4eec\u5fc5\u987b\u5728class\u4e4b\u5916(\u5728\u5168\u57df\u8303\u56f4\u5185)\uff0c\u5305\u62ec\u4e00\u4e2a\u6b63\u5f0f\u7684\u5b9a\u4e49\uff0c\u5c31\u50cf\u4e0a\u9762\u4f8b\u5b50\u4e2d\u505a\u6cd5\u4e00\u6837\u3002\u56e0\u4e3a\u5b83\u5bf9\u540c\u4e00\u4e2aclass\u7684\u6240\u6709object\u662f\u540c\u4e00\u4e2a\u503c\uff0c\u6240\u4ee5\u5b83\u53ef\u4ee5\u88ab\u4f5c\u4e3a\u8be5class\u7684\u4efb\u4f55object\u7684\u6210\u5458\u6240\u5f15\u7528\uff0c\u6216\u8005\u76f4\u63a5\u88ab\u4f5c\u4e3aclass\u7684\u6210\u5458\u5f15\u7528(\u5f53\u7136\u8fd9\u53ea\u9002\u7528\u4e8estatic \u6210\u5458)\uff1acout << a.n;
cout << CDummy::n;\u4ee5\u4e0a\u4e24\u4e2a\u8c03\u7528\u90fd\u6307\u540c\u4e00\u4e2a\u53d8\u91cf\uff1aclass CDummy\u91cc\u7684static \u53d8\u91cf n \u3002\u5728\u63d0\u9192\u4e00\u6b21\uff0c\u5b83\u5176\u5b9e\u662f\u4e00\u4e2a\u5168\u57df\u53d8\u91cf\u3002\u552f\u4e00\u7684\u4e0d\u540c\u662f\u5b83\u7684\u540d\u5b57\u8ddf\u5728class\u7684\u540e\u9762\u3002\u5c31\u50cf\u6211\u4eec\u4f1a\u5728class\u4e2d\u5305\u542bstatic\u6570\u636e\u4e00\u6837\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u4f7f\u5b83\u5305\u542bstatic \u51fd\u6570\u3002\u5b83\u4eec\u8868\u793a\u76f8\u540c\u7684\u542b\u4e49\uff1astatic\u51fd\u6570\u662f\u5168\u57df\u51fd\u6570(global functions)\uff0c\u4f46\u662f\u50cf\u4e00\u4e2a\u6307\u5b9aclass\u7684\u5bf9\u8c61\u6210\u5458\u4e00\u6837\u88ab\u8c03\u7528\u3002\u5b83\u4eec\u53ea\u80fd\u591f\u5f15\u7528static \u6570\u636e\uff0c\u6c38\u8fdc\u4e0d\u80fd\u5f15\u7528class\u7684\u975e\u9759\u6001(nonstatic)\u6210\u5458\u3002\u5b83\u4eec\u4e5f\u4e0d\u80fd\u591f\u4f7f\u7528\u5173\u952e\u5b57this\uff0c\u56e0\u4e3athis\u5b9e\u9645\u5f15\u7528\u4e86\u4e00\u4e2a\u5bf9\u8c61\u6307\u9488\uff0c\u4f46\u8fd9\u4e9b static\u51fd\u6570\u5374\u4e0d\u662f\u4efb\u4f55object\u7684\u6210\u5458\uff0c\u800c\u662fclass\u7684\u76f4\u63a5\u6210\u5458\u3002<\/code><\/p>\n","protected":false},"excerpt":{"rendered":"
4.2 \u64cd\u4f5c\u7b26\u91cd\u8f7d\uff08Overloading operators\uff09 C++ \u5b9e\u73b0\u4e86\u5728\u7c7b(class)\u4e4b\u95f4\u4f7f\u7528\u8bed\u8a00\u6807\u51c6\u64cd\u4f5c\u7b26\uff0c\u800c\u4e0d\u53ea\u662f\u5728\u57fa\u672c\u6570\u636e\u7c7b\u578b\u4e4b\u95f4\u4f7f\u7528\u3002\u4f8b\u5982\uff1aint a, b, c;a = b + c; \u662f\u6709\u6548\u64cd\u4f5c\uff0c\u56e0\u4e3a\u52a0\u53f7\u4e24\u8fb9\u7684\u53d8\u91cf\u90fd\u662f\u57fa\u672c\u6570\u636e\u7c7b\u578b\u3002\u7136\u800c\uff0c\u6211\u4eec\u662f\u5426\u53ef\u4ee5\u8fdb\u884c\u4e0b\u9762\u7684\u64cd\u4f5c\u5c31\u4e0d\u662f\u90a3\u4e48\u663e\u800c\u6613\u89c1\u4e86\uff08\u5b83\u5b9e\u9645\u4e0a\u662f\u6b63\u786e\u7684\uff09\uff1astruct { char product [50]; float price; } a, b, c;a = b + c; \u5c06\u4e00\u4e2a\u7c7bclass (\u6216\u7ed3\u6784struct)\u7684\u5bf9\u8c61\u8d4b\u7ed9\u53e6\u4e00\u4e2a\u540c\u79cd\u7c7b\u578b\u7684\u5bf9\u8c61\u662f\u5141\u8bb8\u7684(\u901a\u8fc7\u4f7f\u7528\u9ed8\u8ba4\u7684\u590d\u5236\u6784\u9020\u51fd\u6570 copy constructor)\u3002\u4f46\u76f8\u52a0\u64cd\u4f5c\u5c31\u6709\u53ef\u80fd\u4ea7\u751f\u9519\u8bef\uff0c\u7406\u8bba\u4e0a\u8bb2\u5b83\u5728\u975e\u57fa\u672c\u6570\u636e\u7c7b\u578b\u4e4b\u95f4\u662f\u65e0\u6548\u7684\u3002 \u4f46\u5f52\u529f\u4e8eC++ \u7684\u64cd\u4f5c\u7b26\u91cd\u8f7d\uff08overload\uff09\u80fd\u529b\uff0c\u6211\u4eec\u53ef\u4ee5\u5b8c\u6210\u8fd9\u4e2a\u64cd\u4f5c\u3002\u50cf\u4ee5\u4e0a\u4f8b\u5b50\u4e2d\u8fd9\u6837\u7684\u7ec4\u5408\u7c7b\u578b\u7684\u5bf9\u8c61\u5728C++\u4e2d\u53ef\u4ee5\u63a5\u53d7\u5982\u679c\u6ca1\u6709\u64cd\u4f5c\u7b26\u91cd\u8f7d\u5219\u4e0d\u80fd\u88ab\u63a5\u53d7\u7684\u64cd\u4f5c\uff0c\u6211\u4eec\u751a\u81f3\u53ef\u4ee5\u4fee\u6539\u8fd9\u4e9b\u64cd\u4f5c\u7b26\u7684\u6548\u679c\u3002\u4ee5\u4e0b\u662f\u6240\u6709\u53ef\u4ee5\u88ab\u91cd\u8f7d\u7684\u64cd\u4f5c\u7b26\u7684\u5217\u8868\uff1a + – * \/ = < > += -= *= \/= << >> <<= >>= == != <= >= ++ — % […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":351,"menu_order":1,"comment_status":"closed","ping_status":"closed","template":"","meta":[],"_links":{"self":[{"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/pages\/355"}],"collection":[{"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/comments?post=355"}],"version-history":[{"count":1,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/pages\/355\/revisions"}],"predecessor-version":[{"id":356,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/pages\/355\/revisions\/356"}],"up":[{"embeddable":true,"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/pages\/351"}],"wp:attachment":[{"href":"https:\/\/www.prglab.com\/blog\/wp-json\/wp\/v2\/media?parent=355"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}