[問題]編譯完出現 undefined reference to

看板C_and_CPP作者 (柴柴可愛)時間7年前 (2017/03/31 04:29), 7年前編輯推噓4(402)
留言6則, 3人參與, 最新討論串1/1
開發平台(Platform): (Ex: Win10, Linux, ...) linux 編譯器(Ex: GCC, clang, VC++...)+目標環境(跟開發平台不同的話需列出) 額外使用到的函數庫(Library Used): (Ex: OpenGL, ...) 問題(Question): 大家好,剛接觸C++沒多久(以前學c),還不太熟悉請多指教。 編譯完後出現一群undefined reference to, 我覺得應該是在講class R的問題,可是檢查了R找不出錯在哪... 詳細狀況如下: /tmp/ccY2jGY2.o: In function `R::R(int, int)': test.cpp:(.text._ZN1RC2Eii[_ZN1RC5Eii]+0x13): undefined reference to `R::r1' test.cpp:(.text._ZN1RC2Eii[_ZN1RC5Eii]+0x1c): undefined reference to `R::r2' /tmp/ccY2jGY2.o: In function `R::now()': test.cpp:(.text._ZN1R3nowEv[_ZN1R3nowEv]+0x10): undefined reference to `R::r1' /tmp/ccY2jGY2.o: In function `R::Ans(float)': test.cpp:(.text._ZN1R3AnsEf[_ZN1R3AnsEf]+0x68): undefined reference to `R::s' test.cpp:(.text._ZN1R3AnsEf[_ZN1R3AnsEf]+0x6e): undefined reference to `R::r1' test.cpp:(.text._ZN1R3AnsEf[_ZN1R3AnsEf]+0x7f): undefined reference to `R::s' test.cpp:(.text._ZN1R3AnsEf[_ZN1R3AnsEf]+0x90): undefined reference to `R::r2' test.cpp:(.text._ZN1R3AnsEf[_ZN1R3AnsEf]+0x96): undefined reference to `R::r1' test.cpp:(.text._ZN1R3AnsEf[_ZN1R3AnsEf]+0xff): undefined reference to `R::r1' test.cpp:(.text._ZN1R3AnsEf[_ZN1R3AnsEf]+0x105): undefined reference to `R::r1' collect2: error: ld returned 1 exit status 餵入的資料(Input): 預期的正確結果(Expected Output): 錯誤結果(Wrong Output): 程式碼(Code):(請善用置底文網頁, 記得排版) codePad:https://codepad.remoteinterview.io/HUAVHCNAJT #include <iostream> #include <cmath> #include <cstdlib> # include <iostream> # include <string> # include <fstream> using namespace std; //專門拿來算R的class class R{ public: int ans;//所求 R(){ cerr<<"no data to calculate"; } R(int r1_,int r2_){ r1=r1_; r2=r2_; } //還沒有輸入s值的R值 int now(){ ans=r1; return ans; } //有輸入s的R值 int Ans(float s_){ //s 只有三種:1 ,0 ,0.5 if (s_==1||s_==0||s_==0.5){ s=s_; } else{ cerr<<"need to be 1 0.5 0"; exit(1); } r1=r1+k*(s-(1/(1+pow(10,(r2 - r1/400))))); //R的計算公式 ans=r1; return ans; } private: static int r1,r2; static float s; static const int k=32; }; int main(){ ofstream outFile("filein.txt",ios::out);//先做一個filein.txt if(!outFile) { cerr<<"err\n"; exit(1); } //輸入原始數據 outFile << "k\tr1\tr2\n"; outFile << 32<<"\t"<<1613<<"\t"<<1609<<endl; outFile << "sa\tsb\n"; outFile << 0 <<"\t"<< (1-0)<<"\t"<<endl; outFile << 0.5 <<"\t"<< (1-0.5)<<"\t"<<endl; outFile << 0.5 <<"\t"<< (1-0.5)<<"\t"<<endl; outFile << 0 <<"\t"<< (1-0)<<"\t"<<endl; outFile << 0 <<"\t"<< (1-0)<<"\t"<<endl; outFile << 0 <<"\t"<< (1-0)<<"\t"<<endl; outFile.close(); //接下來要開始讀filein,txt,然後寫一個fileout.txt //宣告,等一下會用到 string headline1, headline2; int r1,r2,k; float pointa,pointb;//s值 ifstream inFile("filein.txt",ios::in); ofstream ouFile("fileout.txt",ios::out); //成功? if(!inFile){ cerr<<"filein.txt fail"; exit(1); } if(!ouFile){ cerr<<"fileout.txt fail"; exit(1); } //開始讀檔 getline(inFile,headline1); inFile>>k>>r1>>r2; R ra(r1,r2); //初始化ra R rb(r2,r1); //初始化rb ouFile<< ra.now()<<"\t"<< rb.now()<<"\n"; //ra rb原封不動寫入fileout.txt //開始讀s值 while(inFile>>pointa>>pointb){ ouFile<< ra.Ans(pointa)<<"\t"<< rb.Ans(pointb)<<"\n"; //算一算寫入fileout.txt// } inFile.close(); ouFile.close(); } 補充說明(Supplement):*[m 這裡的R是在算Elo rate。 s是指每次勝負的得分。贏者得一分,輸了零分,平手0. 5 研究了很久都不了,拜託幫忙了 -- ※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 218.164.190.214 ※ 文章網址: https://www.ptt.cc/bbs/C_and_CPP/M.1490905771.A.9FB.html ※ 編輯: franklin1997 (218.164.190.214), 03/31/2017 04:34:08 ※ 編輯: franklin1997 (218.164.190.214), 03/31/2017 04:34:49

03/31 04:37, , 1F
你需要 init static data member 吧
03/31 04:37, 1F

03/31 04:38, , 2F
找個地方初始化你class 的r1
03/31 04:38, 2F

03/31 04:39, , 3F
話說static 真的是你要的嗎
03/31 04:39, 3F
呃 應該是不用沒錯(打程式的時候自己混亂了 我睡一下再改改看 甘溫 ※ 編輯: franklin1997 (36.238.194.129), 03/31/2017 05:00:50

03/31 07:30, , 4F
問題有夠明顯,static data member寫在類裡面只是聲
03/31 07:30, 4F

03/31 07:30, , 5F
明,非定義
03/31 07:30, 5F
我把那兩個static刪掉了,謝謝兩位大大 ※ 編輯: franklin1997 (36.238.194.129), 03/31/2017 11:28:37

04/07 03:00, , 6F
難怪我覺得這問題好眼熟XDD 這是算elo的對吧XDD
04/07 03:00, 6F
文章代碼(AID): #1OtMghdx (C_and_CPP)