{"id":4470,"date":"2020-12-28T21:26:08","date_gmt":"2020-12-28T13:26:08","guid":{"rendered":"https:\/\/yanjingang.com\/blog\/?p=4470"},"modified":"2020-12-29T18:23:58","modified_gmt":"2020-12-29T10:23:58","slug":"c%e7%9a%84%e6%8c%87%e9%92%88%e4%b8%8e%e5%bc%95%e7%94%a8","status":"publish","type":"post","link":"https:\/\/yanjingang.com\/blog\/?p=4470","title":{"rendered":"C++\u7684\u6307\u9488*\u4e0e\u5f15\u7528&"},"content":{"rendered":"

\u7b80\u5355\u7406\u89e3\u4e0b\uff1a<\/p>\n

1.\u5b9a\u4e49\u53d8\u91cf\u65f6<\/h1>\n

\u4f8b\u5982int* ptr = &var; <\/code>prt\u6307\u9488\u5b58\u7684\u662f\u53d8\u91cf\u5185\u5b58\u5730\u5740\uff1b<\/p>\n

\u4f8b\u5982int& ref = var; <\/code>ref\u5f15\u7528\u662f\u7ed9var\u53d8\u91cf\u8d77\u5916\u53f7\uff0c\u6307\u5411var\u76f8\u540c\u7684\u5185\u5b58\u5730\u5740\uff1b<\/p>\n

2.\u8bfb\u53d6\u53d8\u91cf\u65f6<\/h1>\n

\u4f8b\u5982*ptr<\/code>\uff0c<\/code>\u662f\u7528*\u83b7\u53d6\u6307\u9488ptr\u6307\u5411\u5185\u5b58\u5730\u5740\u91cc\u4fdd\u5b58\u7684\u53d8\u91cf\u503c\uff1b<\/p>\n

\u4f8b\u5982&var\uff0c<\/code>\u662f\u7528&\u83b7\u53d6\u666e\u901a\u53d8\u91cfvar\u7684\u5185\u5b58\u5730\u5740\uff1b<\/p>\n

3.\u4f5c\u4e3a\u51fd\u6570\u53c2\u6570\u65f6<\/h1>\n

\u4f8b\u5982void fun(int* a){int b = 0; *a = b;}\uff0c\u51fd\u6570\u5185\u4fee\u6539*a\u4f1a\u5f71\u54cd\u51fd\u6570\u5916\u4f20\u5165\u7684\u53c2\u6570\u53d8\u91cf\u503c
\n\u4f8b\u5982void fun(int& a){int b = 0; a = b;}\uff0c\u51fd\u6570\u5185\u4fee\u6539a\u4f1a\u5f71\u54cd\u51fd\u6570\u5916\u4f20\u5165\u7684\u53c2\u6570\u53d8\u91cf\u503c<\/p>\n

4.\u4ee3\u7801\u6d4b\u8bd5<\/h1>\n
\/\/ \u6307\u9488\u53c2\u6570\u4fee\u6539\u6d4b\u8bd5\r\nvoid modify_ptr(int* a){\r\n  int b = 99;\r\n  *a = b;\r\n}\r\n\/\/ \u5f15\u7528\u53c2\u6570\u4fee\u6539\u6d4b\u8bd5\r\nvoid modify_ref(int& a){\r\n  int b = 88;\r\n  a = b;\r\n}\r\n\r\n\r\nint main(int argc, char* argv[])\r\n{\r\n  \/\/ \u6307\u9488\u3001\u5f15\u7528\r\n  LOG(INFO) << \"test *\/&:\" << endl;\r\n  int var = 3000;\r\n  int* ptr = &var; \/\/ \u5b9a\u4e49\u4e00\u4e2a\u6307\u9488\uff0c\u7528&\u83b7\u53d6\u666e\u901a\u53d8\u91cfvar\u7684\u5730\u5740\r\n  int& ref = var; \/\/ \u5b9a\u4e49\u4e00\u4e2a\u5f15\u7528\u53d8\u91cf\uff0c\u6307\u5411var\u7684\u5730\u5740(\u5f15\u7528\u53d8\u91cfref\u672c\u8eab\u4e0evar\u662f\u4e00\u6837\u7684\uff0c\u6307\u5411\u4e86\u540c\u4e00\u5757\u5185\u5b58\u5730\u5740\uff0c\u76f8\u5f53\u4e8e\u8d77\u4e86\u4e2a\u5916\u53f7)\r\n  \/\/int& ref = *ptr;    \/\/\u540c\u4e0a\r\n  int val = *ptr;\/\/ \u5b9a\u4e49\u4e00\u4e2a\u53d8\u91cf\uff0c\u7528*\u83b7\u53d6\u6307\u9488\u53d8\u91cfptr\u7684\u503c\r\n  *ptr = 100; \/\/ \u6539\u53d8ptr\u6307\u9488\u6307\u5411\u7684\u503c\uff0c\u4f1a\u5bfc\u81f4var\u7684\u503c\u4e5f\u88ab\u4fee\u6539\uff0c\u4f46\u4e0d\u4f1a\u5f71\u54cdval\u3002\u56e0\u4e3a*ptr\u6307\u5411\u4e86var\u53d8\u91cf\u7684\u5730\u5740\uff0c\u800cval\u53ea\u662f\u53bb\u4e86ptr\u7684\u503c\u800c\u6ca1\u6709\u6307\u9488\u76f8\u8fde\r\n  cout << \"Value of var :\" << var << endl;\r\n  cout << \"Value of &var :\" << &var << endl;\r\n  cout << \"Value of ptr :\" << ptr << endl;\r\n  cout << \"Value of *ptr :\" << *ptr << endl;\r\n  cout << \"Value of ref :\" << ref << endl;\r\n  cout << \"Value of &ref :\" << &ref << endl;\r\n  cout << \"Value of val :\" << val << endl;\r\n\r\n  \/\/ \u6307\u9488\u3001\u5f15\u7528\u53c2\u6570\r\n  LOG(INFO) << \"test func *\/& param:\" << endl;\r\n  modify_ptr(&var);   \r\n  cout << \"Value of var :\" << var << endl;\r\n  modify_ptr(ptr);    \/\/\u540c\u4e0a\r\n  cout << \"Value of *ptr :\" << *ptr << endl;\r\n\r\n  modify_ref(var);\r\n  cout << \"Value of val :\" << var << endl;\r\n  modify_ref(ref);    \/\/\u540c\u4e0a\r\n  cout << \"Value of ref :\" << ref << endl;\r\n}\r\n\r\n\r\n\/\/ \u6253\u5370\u7ed3\u679c\r\nI1228 21:51:50.451804 432086464 main.cc:294] test *\/&:\r\nValue of var :100\r\nValue of &var :0x7ffee3f1aa5c\r\nValue of ptr :0x7ffee3f1aa5c\r\nValue of *ptr :100\r\nValue of ref :100\r\nValue of &ref :0x7ffee3f1aa5c\r\nValue of val :3000\r\nI1228 21:51:50.451846 432086464 main.cc:310] test func *\/& param:\r\nValue of var :99\r\nValue of *ptr :99\r\nValue of val :88\r\nValue of ref :88\r\n<\/code><\/pre>\n
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\u53c2\u8003\uff1ahttps:\/\/blog.csdn.net\/weixin_42878758\/article\/details\/82865314<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"
\u7b80\u5355\u7406\u89e3\u4e0b\uff1a 1.\u5b9a\u4e49\u53d8\u91cf\u65f6 \u4f8b\u5982int* ptr = &var; prt\u6307\u9488\u5b58\u7684\u662f\u53d8\u91cf\u5185\u5b58\u5730\u5740\uff1b \u4f8b […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1027],"tags":[877,1037,1036],"_links":{"self":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/4470"}],"collection":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4470"}],"version-history":[{"count":0,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/4470\/revisions"}],"wp:attachment":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4470"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4470"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4470"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}