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Dog",[932,1099,1040],{"class":942},[932,1101,1043],{"class":968},[932,1103,973],{"class":972},[932,1105,976],{"class":942},[932,1107,1109,1111,1113,1115,1117,1119,1121],{"class":934,"line":1108},14,[932,1110,982],{"class":972},[932,1112,985],{"class":942},[932,1114,947],{"class":972},[932,1116,991],{"class":990},[932,1118,994],{"class":942},[932,1120,997],{"class":968},[932,1122,976],{"class":942},[932,1124,1126,1128,1130,1133,1135],{"class":934,"line":1125},15,[932,1127,1005],{"class":938},[932,1129,1008],{"class":942},[932,1131,1132],{"class":946},"dog",[932,1134,1014],{"class":942},[932,1136,1017],{"class":942},[932,1138,1140],{"class":934,"line":1139},16,[932,1141,1084],{"class":942},[932,1143,1145],{"class":934,"line":1144},17,[932,1146,1029],{"class":942},[932,1148,1150],{"class":934,"line":1149},18,[932,1151,1153],{"emptyLinePlaceholder":1152},true,"\n",[932,1155,1157,1160,1163,1165],{"class":934,"line":1156},19,[932,1158,1159],{"class":968},"int",[932,1161,1162],{"class":990}," main",[932,1164,994],{"class":942},[932,1166,976],{"class":942},[932,1168,1170,1174,1177,1180],{"class":934,"line":1169},20,[932,1171,1173],{"class":1172},"sTEyZ","    Animal",[932,1175,1176],{"class":942},"*",[932,1178,1179],{"class":1172}," pet",[932,1181,1182],{"class":942},"{nullptr};\n",[932,1184,1186,1188,1190,1193,1196,1198,1201,1203,1206,1209,1211,1214],{"class":934,"line":1185},21,[932,1187,982],{"class":972},[932,1189,985],{"class":942},[932,1191,1192],{"class":1172},"cout ",[932,1194,1195],{"class":942},"\u003C\u003C",[932,1197,1008],{"class":942},[932,1199,1200],{"class":946},"If you want a cat, press 1.",[932,1202,1014],{"class":942},[932,1204,1205],{"class":942}," \u003C\u003C",[932,1207,1208],{"class":972}," std",[932,1210,985],{"class":942},[932,1212,1213],{"class":1172},"endl",[932,1215,1017],{"class":942},[932,1217,1219,1222,1225],{"class":934,"line":1218},22,[932,1220,1221],{"class":968},"    int",[932,1223,1224],{"class":1172}," n",[932,1226,1017],{"class":942},[932,1228,1230,1232,1234,1237,1240,1242],{"class":934,"line":1229},23,[932,1231,982],{"class":972},[932,1233,985],{"class":942},[932,1235,1236],{"class":1172},"cin ",[932,1238,1239],{"class":942},">>",[932,1241,1224],{"class":1172},[932,1243,1017],{"class":942},[932,1245,1247,1250,1253,1256,1259,1263,1266],{"class":934,"line":1246},24,[932,1248,1249],{"class":938},"    if",[932,1251,1252],{"class":942}," (",[932,1254,1255],{"class":1172},"n ",[932,1257,1258],{"class":942},"==",[932,1260,1262],{"class":1261},"sbssI"," 1",[932,1264,1265],{"class":942},")",[932,1267,976],{"class":942},[932,1269,1271,1275,1278,1281,1283],{"class":934,"line":1270},25,[932,1272,1274],{"class":1273},"swJcz","        pet ",[932,1276,1277],{"class":942},"=",[932,1279,1280],{"class":942}," new",[932,1282,1037],{"class":1273},[932,1284,1285],{"class":942},"{};\n",[932,1287,1289,1292,1295],{"class":934,"line":1288},26,[932,1290,1291],{"class":942},"    }",[932,1293,1294],{"class":938}," else",[932,1296,976],{"class":942},[932,1298,1300,1302,1304,1306,1308],{"class":934,"line":1299},27,[932,1301,1274],{"class":1273},[932,1303,1277],{"class":942},[932,1305,1280],{"class":942},[932,1307,1097],{"class":1273},[932,1309,1285],{"class":942},[932,1311,1313],{"class":934,"line":1312},28,[932,1314,1023],{"class":942},[932,1316,1318,1320,1322,1324,1326,1328,1331,1333,1335,1337,1340,1343,1345,1347,1349,1351,1353],{"class":934,"line":1317},29,[932,1319,982],{"class":972},[932,1321,985],{"class":942},[932,1323,1192],{"class":1172},[932,1325,1195],{"class":942},[932,1327,1008],{"class":942},[932,1329,1330],{"class":946},"Here is your new ",[932,1332,1014],{"class":942},[932,1334,1205],{"class":942},[932,1336,1179],{"class":1172},[932,1338,1339],{"class":942},"->",[932,1341,1342],{"class":990},"getName",[932,1344,994],{"class":942},[932,1346,1205],{"class":942},[932,1348,1208],{"class":972},[932,1350,985],{"class":942},[932,1352,1213],{"class":1172},[932,1354,1017],{"class":942},[932,1356,1358,1361,1363],{"class":934,"line":1357},30,[932,1359,1360],{"class":942},"    delete",[932,1362,1179],{"class":1172},[932,1364,1017],{"class":942},[932,1366,1368],{"class":934,"line":1367},31,[932,1369,1370],{"class":942},"}\n",[918,1372,1373,1374,1377,1378,1381,1382,1385,1386,1389],{},"上面这段代码试图实现这样的功能：根据用户的输入决定指针 ",[929,1375,1376],{},"pet"," 指向的类型：如果输入为 ",[929,1379,1380],{},"1"," 则指向一个新的 ",[929,1383,1384],{},"Cat"," 对象，否则指向一个新的 ",[929,1387,1388],{},"Dog"," 对象，然后把它的名字输出。看上去挺像那么回事儿，但它并不工作。你会发现，不管你输入什么，输出的总是",[1391,1392,1393],"io-block",{},[918,1394,1395],{},"Here is your new animal",[918,1397,1398,1399,1401,1402,1404,1405,1407,1408,1410,1411,1414,1415,1417,1418,1421,1422,1424,1425,1428,1429,1431],{},"而不是 ",[929,1400,1074],{}," 或者 ",[929,1403,1132],{},"。奇怪，在 ",[929,1406,1384],{}," 类的 ",[929,1409,1342],{}," 成员函数的返回值不是 ",[929,1412,1413],{},"\"cat\""," 么？讲道理，如果输入为 ",[929,1416,1380],{},"，当执行 ",[929,1419,1420],{},"new Cat"," 之后，",[929,1423,1376],{}," 指向的这个对象的 ",[929,1426,1427],{},"getName()"," 调用应该得到 ",[929,1430,1413],{}," 呀。",[918,1433,1434,1435,1437,1438,1440,1441,1444,1445,1448,1449,1444,1452,1454],{},"问题出现在之前提到的继承中成员名的处理方式上了。当派生类中出现一个和基类名字相同的成员时，并不会覆盖基类的成员实现，而是在保留基类成员的同时增加一个同名派生类成员。也就是说，",[929,1436,1420],{}," 中包含两份 ",[929,1439,1342],{},"，其中一个是 ",[929,1442,1443],{},"Animal::getName","，返回 ",[929,1446,1447],{},"\"animal\"","；另一个是 ",[929,1450,1451],{},"Cat::getName",[929,1453,1413],{},"。",[918,1456,1457,1458,1461,1462,1465,1466,1468,1469,1471,1472,1474,1475,1478,1479,1481,1482,1485,1486,1488,1489,1485,1492,1495,1496,1499,1500,1502,1503,1505,1506,1454],{},"那么现在执行 ",[929,1459,1460],{},"pet->getName()","，或者说 ",[929,1463,1464],{},"(*pet).getName()"," 时，找到的是 ",[929,1467,1443],{}," 还是 ",[929,1470,1451],{}," 呢？前面说过，这里省略的作用域是左侧操作数的类型。也就是说，这个 ",[929,1473,1342],{}," 是哪个取决于 ",[929,1476,1477],{},"(*pet)"," 的类型—— ",[929,1480,1376],{}," 是 ",[929,1483,1484],{},"Animal*"," 类型的，那么 ",[929,1487,1477],{}," 自然就是 ",[929,1490,1491],{},"Animal",[929,1493,1494],{},"(*pet).getName"," 就相当于 ",[929,1497,1498],{},"(*pet).Animal::getName","！所以，不论是猫是狗，最终执行的总是 ",[929,1501,1443],{},"，不会是我们想要的 ",[929,1504,1451],{}," 或 ",[929,1507,1508],{},"Dog::getName",[918,1510,1511],{},"于是怎么办呢？C++ 提供了虚函数机制，它可用于重写（或者说覆盖）基类的成员函数。",[918,1513,1514,1515,1517,1518,1521],{},"对于我们这个例子，它的实现很简单：在 ",[929,1516,1443],{}," 前面加上 ",[929,1519,1520],{},"virtual"," 关键字修饰即可：",[922,1523,1525],{"className":924,"code":1524,"language":926,"meta":927,"style":927},"struct Animal {\n    virtual std::string getName() const {\n        return \"animal\";\n    }\n};\n",[929,1526,1527,1535,1554,1566,1570],{"__ignoreMap":927},[932,1528,1529,1531,1533],{"class":934,"line":935},[932,1530,969],{"class":968},[932,1532,973],{"class":972},[932,1534,976],{"class":942},[932,1536,1537,1540,1542,1544,1546,1548,1550,1552],{"class":934,"line":953},[932,1538,1539],{"class":968},"    virtual",[932,1541,1208],{"class":972},[932,1543,985],{"class":942},[932,1545,947],{"class":972},[932,1547,991],{"class":990},[932,1549,994],{"class":942},[932,1551,997],{"class":968},[932,1553,976],{"class":942},[932,1555,1556,1558,1560,1562,1564],{"class":934,"line":965},[932,1557,1005],{"class":938},[932,1559,1008],{"class":942},[932,1561,1011],{"class":946},[932,1563,1014],{"class":942},[932,1565,1017],{"class":942},[932,1567,1568],{"class":934,"line":979},[932,1569,1023],{"class":942},[932,1571,1572],{"class":934,"line":1002},[932,1573,1029],{"class":942},[918,1575,1576,1577,1579],{},"然后再跑一遍程序，一切输出就都正常了。像这样被 ",[929,1578,1520],{}," 修饰的成员函数就是虚函数了，它是实现子类型多态的一个重要组成部分。",[1581,1582,1583],"h2",{"id":1583},"什么是虚函数",[918,1585,1586,1587,1591,1592,1595,1596,1599,1600,1603,1604,1607,1608,1610,1611,1613,1614,1616,1617,1619],{},"虚函数（Virtual function）是一种特殊的成员函数。形象地讲，其特殊性在于它可以",[1588,1589,1590],"strong",{},"被派生类的同名成员函数覆盖","。比如对于 ",[929,1593,1594],{},"Base"," 类的虚函数 ",[929,1597,1598],{},"Base::f","，如果它拥有一个子类 ",[929,1601,1602],{},"Derived","，且子类也定义了同名的函数 ",[929,1605,1606],{},"Derived::f","， 则在某些时刻下，本应调用 ",[929,1609,1598],{}," 的场合实际却调用了 ",[929,1612,1606],{},"：或者说 ",[929,1615,1598],{}," 的调用被 ",[929,1618,1606],{}," 所覆盖。",[918,1621,1622],{},"那么上文中的“某些时刻”是什么时刻呢？唯有以下两种情形会发生：",[1624,1625,1626,1636],"ol",{},[1627,1628,1629,1632,1633,1635],"li",{},[929,1630,1631],{},"Base*"," 类型的指针，却指向一个 ",[929,1634,1602],{}," 类型的对象；",[1627,1637,1638,1641,1642,1644],{},[929,1639,1640],{},"Base&"," 类型的引用，却绑定到一个 ",[929,1643,1602],{}," 类型的对象。",[918,1646,1647],{},"这时，如果对这样的指针做成员函数调用一个虚函数：",[922,1649,1651],{"className":924,"code":1650,"language":926,"meta":927,"style":927},"Derived d;\nBase* pb{&d};\nBase& rb{d};\npb->f(); \u002F\u002F 通过 Base* 调用虚函数\nrb.f();  \u002F\u002F 通过 Base& 调用虚函数\n",[929,1652,1653,1660,1677,1694,1711],{"__ignoreMap":927},[932,1654,1655,1658],{"class":934,"line":935},[932,1656,1657],{"class":1172},"Derived d",[932,1659,1017],{"class":942},[932,1661,1662,1664,1666,1669,1672,1675],{"class":934,"line":953},[932,1663,1594],{"class":1172},[932,1665,1176],{"class":942},[932,1667,1668],{"class":1172}," pb",[932,1670,1671],{"class":942},"{&",[932,1673,1674],{"class":1273},"d",[932,1676,1029],{"class":942},[932,1678,1679,1681,1684,1687,1690,1692],{"class":934,"line":965},[932,1680,1594],{"class":1172},[932,1682,1683],{"class":942},"&",[932,1685,1686],{"class":1172}," rb",[932,1688,1689],{"class":942},"{",[932,1691,1674],{"class":1273},[932,1693,1029],{"class":942},[932,1695,1696,1699,1701,1704,1707],{"class":934,"line":979},[932,1697,1698],{"class":1172},"pb",[932,1700,1339],{"class":942},[932,1702,1703],{"class":990},"f",[932,1705,1706],{"class":942},"();",[932,1708,1710],{"class":1709},"sHwdD"," \u002F\u002F 通过 Base* 调用虚函数\n",[932,1712,1713,1716,1719,1721,1723],{"class":934,"line":1002},[932,1714,1715],{"class":1172},"rb",[932,1717,1718],{"class":942},".",[932,1720,1703],{"class":990},[932,1722,1706],{"class":942},[932,1724,1725],{"class":1709},"  \u002F\u002F 通过 Base& 调用虚函数\n",[918,1727,1728,1729,1732,1733,1735,1736,1454],{},"那么，此时实际被调用的是 ",[929,1730,1731],{},"Derived::f()","。反之，如果 ",[929,1734,1703],{}," 不是虚的，那么调用的就是 ",[929,1737,1738],{},"Base::f()",[918,1740,1741,1742,1744],{},"显然，典型的虚函数的写法是在成员函数前加以 ",[929,1743,1520],{}," 关键字限定：",[1746,1747,1748],"sdsc",{},[918,1749,1750,1751,1754,1755,1758],{},"\"virtual\" ",[932,1752,1753],{},"返回值类型"," 成员函数名\"(\"",[932,1756,1757],{},"参数列表","\")\" 函数体",[1581,1760,1761],{"id":1761},"注意事项",[918,1763,1764],{},"在成员函数中也可调用虚函数。",[922,1766,1768],{"className":924,"code":1767,"language":926,"meta":927,"style":927},"#include \u003Ciostream>\nstruct Base {\n    void callF() {\n        f(); \u002F\u002F 相当于 this->f();\n    }\n    virtual void f() { \u002F\u002F 虚函数，可被子类覆盖\n        std::cout \u003C\u003C \"Base called\" \u003C\u003C std::endl;\n    }\n};\nstruct Derived : Base {\n    void f() {\n        std::cout \u003C\u003C \"Derived called\" \u003C\u003C std::endl;\n    }\n};\nint main() {\n    Base* b{new Derived{}};\n    b->callF(); \u002F\u002F 输出 Derived called\n}\n",[929,1769,1770,1780,1789,1801,1811,1815,1833,1861,1865,1869,1884,1894,1921,1925,1929,1939,1957,1972],{"__ignoreMap":927},[932,1771,1772,1774,1776,1778],{"class":934,"line":935},[932,1773,939],{"class":938},[932,1775,943],{"class":942},[932,1777,960],{"class":946},[932,1779,950],{"class":942},[932,1781,1782,1784,1787],{"class":934,"line":953},[932,1783,969],{"class":968},[932,1785,1786],{"class":972}," Base",[932,1788,976],{"class":942},[932,1790,1791,1794,1797,1799],{"class":934,"line":965},[932,1792,1793],{"class":968},"    void",[932,1795,1796],{"class":990}," callF",[932,1798,994],{"class":942},[932,1800,976],{"class":942},[932,1802,1803,1806,1808],{"class":934,"line":979},[932,1804,1805],{"class":990},"        f",[932,1807,1706],{"class":942},[932,1809,1810],{"class":1709}," \u002F\u002F 相当于 this->f();\n",[932,1812,1813],{"class":934,"line":1002},[932,1814,1023],{"class":942},[932,1816,1817,1819,1822,1825,1827,1830],{"class":934,"line":1020},[932,1818,1539],{"class":968},[932,1820,1821],{"class":968}," void",[932,1823,1824],{"class":990}," f",[932,1826,994],{"class":942},[932,1828,1829],{"class":942}," {",[932,1831,1832],{"class":1709}," \u002F\u002F 虚函数，可被子类覆盖\n",[932,1834,1835,1838,1840,1842,1844,1846,1849,1851,1853,1855,1857,1859],{"class":934,"line":1026},[932,1836,1837],{"class":972},"        std",[932,1839,985],{"class":942},[932,1841,1192],{"class":1273},[932,1843,1195],{"class":942},[932,1845,1008],{"class":942},[932,1847,1848],{"class":946},"Base called",[932,1850,1014],{"class":942},[932,1852,1205],{"class":942},[932,1854,1208],{"class":972},[932,1856,985],{"class":942},[932,1858,1213],{"class":1273},[932,1860,1017],{"class":942},[932,1862,1863],{"class":934,"line":1032},[932,1864,1023],{"class":942},[932,1866,1867],{"class":934,"line":1050},[932,1868,1029],{"class":942},[932,1870,1871,1873,1876,1878,1881],{"class":934,"line":1067},[932,1872,969],{"class":968},[932,1874,1875],{"class":972}," Derived",[932,1877,1040],{"class":942},[932,1879,1880],{"class":1273}," Base ",[932,1882,1883],{"class":942},"{\n",[932,1885,1886,1888,1890,1892],{"class":934,"line":1081},[932,1887,1793],{"class":968},[932,1889,1824],{"class":990},[932,1891,994],{"class":942},[932,1893,976],{"class":942},[932,1895,1896,1898,1900,1902,1904,1906,1909,1911,1913,1915,1917,1919],{"class":934,"line":1087},[932,1897,1837],{"class":972},[932,1899,985],{"class":942},[932,1901,1192],{"class":1273},[932,1903,1195],{"class":942},[932,1905,1008],{"class":942},[932,1907,1908],{"class":946},"Derived called",[932,1910,1014],{"class":942},[932,1912,1205],{"class":942},[932,1914,1208],{"class":972},[932,1916,985],{"class":942},[932,1918,1213],{"class":1273},[932,1920,1017],{"class":942},[932,1922,1923],{"class":934,"line":1092},[932,1924,1023],{"class":942},[932,1926,1927],{"class":934,"line":1108},[932,1928,1029],{"class":942},[932,1930,1931,1933,1935,1937],{"class":934,"line":1125},[932,1932,1159],{"class":968},[932,1934,1162],{"class":990},[932,1936,994],{"class":942},[932,1938,976],{"class":942},[932,1940,1941,1944,1946,1949,1952,1954],{"class":934,"line":1139},[932,1942,1943],{"class":1172},"    Base",[932,1945,1176],{"class":942},[932,1947,1948],{"class":1172}," b",[932,1950,1951],{"class":942},"{new",[932,1953,1875],{"class":1273},[932,1955,1956],{"class":942},"{}};\n",[932,1958,1959,1962,1964,1967,1969],{"class":934,"line":1144},[932,1960,1961],{"class":1172},"    b",[932,1963,1339],{"class":942},[932,1965,1966],{"class":990},"callF",[932,1968,1706],{"class":942},[932,1970,1971],{"class":1709}," \u002F\u002F 输出 Derived called\n",[932,1973,1974],{"class":934,"line":1149},[932,1975,1370],{"class":942},[918,1977,1978,1979,1982,1983,1986,1987,1990,1991,1993,1994,1996,1997,1999],{},"这是因为成员函数中的成员使用相当于隐含了前缀 ",[929,1980,1981],{},"this->","，而在这里的 ",[929,1984,1985],{},"this->f()"," 和刚刚的情形是一致的，会调用虚函数的实际覆盖函数而非 ",[929,1988,1989],{},"this"," 本身的类型。所以，",[929,1992,1966],{}," 在刚才的例子中调用了 ",[929,1995,1606],{}," 而非 ",[929,1998,1598],{},"。但是，构造函数和析构函数中无法调用到派生类的虚函数覆盖：因为在运行构造函数和析构函数的时期派生类尚未形成或已经消失。",[918,2001,2002],{},"此外，虚函数拥有这样的特点：任何用于覆盖虚函数的子类同名函数，也是虚函数。即：",[922,2004,2006],{"className":924,"code":2005,"language":926,"meta":927,"style":927},"struct A {\n    virtual void f() { }\n};\nstruct B : A {\n    void f() { } \u002F\u002F 尽管没有 virtual 关键字修饰，但它仍然是虚函数\n};\nstruct C : B {\n    void f() { } \u002F\u002F C::f 可能覆盖 B::f，因为后者是虚的\n};\nint main() {\n    B* b;\n    b = new C{};\n    b->f(); \u002F\u002F 调用 C::f 而非 B::f\n    delete b;\n}\n",[929,2007,2008,2017,2032,2036,2050,2066,2070,2084,2099,2103,2113,2124,2137,2150,2158],{"__ignoreMap":927},[932,2009,2010,2012,2015],{"class":934,"line":935},[932,2011,969],{"class":968},[932,2013,2014],{"class":972}," A",[932,2016,976],{"class":942},[932,2018,2019,2021,2023,2025,2027,2029],{"class":934,"line":953},[932,2020,1539],{"class":968},[932,2022,1821],{"class":968},[932,2024,1824],{"class":990},[932,2026,994],{"class":942},[932,2028,1829],{"class":942},[932,2030,2031],{"class":942}," }\n",[932,2033,2034],{"class":934,"line":965},[932,2035,1029],{"class":942},[932,2037,2038,2040,2043,2045,2048],{"class":934,"line":979},[932,2039,969],{"class":968},[932,2041,2042],{"class":972}," B",[932,2044,1040],{"class":942},[932,2046,2047],{"class":1273}," A ",[932,2049,1883],{"class":942},[932,2051,2052,2054,2056,2058,2060,2063],{"class":934,"line":1002},[932,2053,1793],{"class":968},[932,2055,1824],{"class":990},[932,2057,994],{"class":942},[932,2059,1829],{"class":942},[932,2061,2062],{"class":942}," }",[932,2064,2065],{"class":1709}," \u002F\u002F 尽管没有 virtual 关键字修饰，但它仍然是虚函数\n",[932,2067,2068],{"class":934,"line":1020},[932,2069,1029],{"class":942},[932,2071,2072,2074,2077,2079,2082],{"class":934,"line":1026},[932,2073,969],{"class":968},[932,2075,2076],{"class":972}," C",[932,2078,1040],{"class":942},[932,2080,2081],{"class":1273}," B ",[932,2083,1883],{"class":942},[932,2085,2086,2088,2090,2092,2094,2096],{"class":934,"line":1032},[932,2087,1793],{"class":968},[932,2089,1824],{"class":990},[932,2091,994],{"class":942},[932,2093,1829],{"class":942},[932,2095,2062],{"class":942},[932,2097,2098],{"class":1709}," \u002F\u002F C::f 可能覆盖 B::f，因为后者是虚的\n",[932,2100,2101],{"class":934,"line":1050},[932,2102,1029],{"class":942},[932,2104,2105,2107,2109,2111],{"class":934,"line":1067},[932,2106,1159],{"class":968},[932,2108,1162],{"class":990},[932,2110,994],{"class":942},[932,2112,976],{"class":942},[932,2114,2115,2118,2120,2122],{"class":934,"line":1081},[932,2116,2117],{"class":1172},"    B",[932,2119,1176],{"class":942},[932,2121,1948],{"class":1172},[932,2123,1017],{"class":942},[932,2125,2126,2129,2131,2133,2135],{"class":934,"line":1087},[932,2127,2128],{"class":1172},"    b ",[932,2130,1277],{"class":942},[932,2132,1280],{"class":942},[932,2134,2076],{"class":1172},[932,2136,1285],{"class":942},[932,2138,2139,2141,2143,2145,2147],{"class":934,"line":1092},[932,2140,1961],{"class":1172},[932,2142,1339],{"class":942},[932,2144,1703],{"class":990},[932,2146,1706],{"class":942},[932,2148,2149],{"class":1709}," \u002F\u002F 调用 C::f 而非 B::f\n",[932,2151,2152,2154,2156],{"class":934,"line":1108},[932,2153,1360],{"class":942},[932,2155,1948],{"class":1172},[932,2157,1017],{"class":942},[932,2159,2160],{"class":934,"line":1125},[932,2161,1370],{"class":942},[918,2163,2164,2165,2168,2169,2172,2173,2175,2176,2178,2179,2181,2182,2184,2185,2187,2188,2191,2192,1996,2195,1454],{},"在上面的例子中，我们已经知道了可能会发生 ",[929,2166,2167],{},"B::f"," 覆盖 ",[929,2170,2171],{},"A::f"," —— 因为 ",[929,2174,2171],{}," 是虚函数。但正如刚刚所讲，",[929,2177,2167],{}," 因为和 ",[929,2180,2171],{}," 同名，所以 ",[929,2183,2167],{}," 也是虚函数（尽管它没有显式地用 ",[929,2186,1520],{}," 修饰）。所以 ",[929,2189,2190],{},"main"," 函数中的操作会调用 ",[929,2193,2194],{},"C::f",[929,2196,2167],{},[2198,2199,2200],"blockquote",{},[918,2201,2202],{},"虚函数的实现？虚函数表？虚指针？自己找国内那些教材看去。",[2204,2205,2206],"style",{},"html pre.shiki code .s7zQu, html code.shiki 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