使用g 編譯器的架構arm64的未定義符號

我正在嘗試讓一些代碼作業，但無論編譯器如何，我都會收到相同的錯誤。我試圖多載運算子，但出現錯誤。

我有 3 個檔案：main.cpp、vector2d.cpp 和 vector2d.h

這是我用 g 編譯器得到的錯誤：

  Undefined symbols for architecture arm64:
  "v2d::length()", referenced from:
      _main in main-c7db92.o
  "v2d::v2d(v2d const&)", referenced from:
      _main in main-c7db92.o
  "v2d::v2d(double, double)", referenced from:
      _main in main-c7db92.o
  "v2d::~v2d()", referenced from:
      _main in main-c7db92.o
  "v2d::operator=(v2d const&)", referenced from:
      _main in main-c7db92.o
  "v2d::operator*(double)", referenced from:
      _main in main-c7db92.o
  "v2d::operator (v2d const&)", referenced from:
      _main in main-c7db92.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

這是我的 main.cpp

  #include <iostream>
#include "vector2d.h"

using namespace std;

int main() {
    // We crate some vectors with fixed values
    v2d v1(3,0); //(3,0)
    v2d v2(0,4);
    v2d v3(3,2);
    // We create v4 as vector which is like v2
    v2d v4(v2);
    
    cout << "Pythagoras holds on perpendicular triangles (a,b,c):" << endl;
    cout << "a = " << v1.length();
    cout << " , b = " << v2.length();
    
    // We create a new vector v5 by combining other vectors
    // This vector corresponds to the diagonal of the triangle defined by v1 and v2
    v2d v5 = v1   v2 * (-1);
    
    cout << " , c = " << v5.length() << endl;
    
    cout << "...but not on non-perpendicular triangles (a,b,c):" << endl;
    cout << "a = " << v3.length();
    cout << " , b = " << v4.length();
    
    v5 = v3   v4 * (-1);
    
    cout << " , c = " << v5.length() << endl;
    
  
    
    return 0;
}

這是我的 vector2d.cpp

    #include "vector2d.h"
#include <cmath>

v2d::v2d(double a, double b) {
    // Write your code here
}

v2d::v2d(const v2d & v) {
    // Write your code here
}

v2d::~v2d() {
    // Write your code here
}

v2d & v2d::operator=(const v2d &v) {
    // Write your code here
    return *this;
}

v2d & v2d::operator (const v2d &v) {
    // Write your code here
    return *this;
}

double v2d::operator*(const v2d &v) {
    // Write your code here
    return 0;
}

v2d & v2d::operator*(double k) {
    // Write your code here
    return *this;
}

double v2d::length() {
    // Write your code here
    return 0;
}

這是我的 vector2d.h

#ifndef __v2d__
#define __v2d__

class v2d {

public:
    // Standard constructor: builds a vector (a,b)
    v2d(double a, double b);

    // Copy constructor: builds a vector that is exactly as v
    v2d(const v2d & v);

    // Destructor
    ~v2d(void);

    // Assignment operator: updates the vector to make it as v
    v2d & operator=(const v2d &v);

    // Vector addition: updates the vector by adding v
    v2d & operator (const v2d &v);

    // Scalar multiplication: updates the vector by scaling by k
    v2d & operator*(double k);

    // Scalar product of the current vector by another vector v 
    double operator*(const v2d &v);

    // Returns the length of a vector
    double length(void);

private:
    // Internal representation of a vector with just two doubles x and y
    double x;
    double y;

};

#endif

我真的卡住了...

uj5u.com熱心網友回復：

我的猜測是你錯過了添加vector2d.cpp到你的專案中。添加后（使用您使用的任何構建系統）錯誤應該消失。

錯誤表明編譯器試圖在沒有來自該檔案的符號的情況下鏈接程式。

我無法幫助確切地如何添加它，因為它沒有在專案如何構建的問題中指定，但是如果您只想從終端編譯它可能就像

g   main.cpp vector2d.cpp -o program_name
##              ^---- this was probably missing

標籤：C

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