Example of Undefined Reference Error
The below example demonstrates the occurrence of an undefined reference error due to a missing function definition.
C++
// C++ example demonstrating an undefined reference error. #include <iostream> // Declare `newFunction` but don't provide its // implementation. void newFunction(); int main() { // Calling this triggers an error because `newFunction` // is undefined. newFunction(); return 0; } |
Output
/usr/bin/ld: /tmp/cceTEmEf.o: in function `main': main.cpp:(.text+0x9): undefined reference to `newFunction()' collect2: error: ld returned 1 exit status
To resolve this, make sure to provide a proper definition for the function:
C++
// C++ program demonstrating a corrected undefined reference // error #include <iostream> using namespace std; // Function that prints "This is new function" void newFunction() { cout << "This is new function" ; } int main() { newFunction(); return 0; } |
Output
This is new function
What is an Undefined Reference Error in C++?
In C++, an undefined reference is an error that occurs when the linker can’t find the definition of a function or a variable used in the linking stage of the compilation process. This error needs to be resolved for the smooth working of the program.
Contact Us