This is a common linker error that occurs when the entry point `main` function is not defined or is not found in your code. This error typically occurs in C or C++ programs.
Here are a few potential solutions to resolve the "unresolved external symbol main" error:
1. Ensure a valid `main` function: Make sure that your code includes a valid `main` function. In C and C++, the `main` function serves as the entry point of the program. It should have the following signature:
int main()
{
return 0;
}
If you are using a C++ compiler, ensure that the file extension is `.cpp` or `.cxx` to be recognized as a C++ program.
2. Check project configuration: If you are using an integrated development environment (IDE), verify that your project is configured correctly. Check the project settings or build configuration to ensure that it is set up as a console application and that the entry point is correctly defined.
3. Verify file inclusion: Ensure that the source file containing the `main` function is included in your build process. If you have multiple source files, verify that all necessary files are being compiled and linked together.
4. Check for misspellings or case sensitivity: Double-check that the `main` function is spelled correctly and written in lowercase `main()`. The compiler is case-sensitive, so `Main()`, `MAIN()`, or other variations will not be recognized as the entry point.
5. Check build process: If you are using a build system like Makefile or CMake, review the build configuration files to ensure that the necessary source files are being compiled and linked correctly.
By addressing these potential issues, you should be able to resolve the "unresolved external symbol main" error and successfully compile and link your program.