Link Error Cpp
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Undefined Reference To C++ Error
Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with undefined reference to function c++ us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 6.2 million programmers, just c++ linker error unresolved external symbol like you, helping each other. Join them; it only takes a minute: Sign up Linker Error C++ “undefined reference ” [duplicate] up vote 9 down vote favorite 2 Possible Duplicate: What is an undefined reference/unresolved external symbol error and how do I fix it? Trying to compile my program via g++ -o prog1 main.cpp -std=c++0x I
Linker Error Undefined Reference To
get the error: /tmp/cc1pZ8OM.o: In function `main': main.cpp:(.text+0x148): undefined reference to `Hash::insert(int, char)' collect2: error: ld returned 1 exit status main.cpp #include
Practice Problems Quizzes Resources Source Code Source Code Snippets C and C++ Tips Finding a Job References Function Reference Syntax Reference Programming FAQ c++ undefined reference to class Getting Help Message Board Email About Us Dealing with Compiler Errors c++ undefined reference to constructor - Surviving the Compilation Process By Alex Allain It's your first C (or C++) program--it's not that
Undefined Reference To C++ Linux
long, and you're about to compile it. You hit compile (or enter the build command) and wait. Your compiler spits out fifty lines of text. You pick out http://stackoverflow.com/questions/14557657/linker-error-c-undefined-reference words like "warning and "error". Does that mean it worked? you wonder. You look for the resulting executable. Nothing. Damn, you think, I guess I have to figure out what this all means... The Types of Compilation Errors First, let's distinguish between the types of errors: most compilers will give three types of compile-time alerts: compiler warnings, http://www.cprogramming.com/tutorial/compiler_linker_errors.html compiler errors, and linker errors. Although you don't want to ignore them, compiler warnings aren't something severe enough to actually keep your program from compiling. Usually, compiler warnings are an indication that something might go wrong at runtime. How can the compiler know this at all? You might be making a typical mistake that the compiler knows about. A common example is using the assignment operator ('=') instead of the equality operator ('==') inside an if statement. Your compiler may also warn you about using variables that haven't been initialized and other similar mistakes. Generally, you can set the warning level of your compiler--I like to keep it at its highest level so that my compiler warnings don't turn in to bugs in the running program ('runtime bugs'). Nevertheless, compiler warnings aren't going to stop you from getting your program working (unless you tell your compiler to treat warnings as errors), so they're probably a bit less frustrating than errors. Errors are conditions that prevent the compiler from co
some background. What is the linker? Consider the framework of a typical C++ program shown below. The main program in main.cpp uses a class called Type1, declared in the file type1.h-no executable code http://inst.eecs.berkeley.edu/~selfpace/studyguide/9F.sg/Output/linker.errors.html appears here-and defined, with executable code, in the file type1.cpp. A private class variable http://www.csee.umbc.edu/courses/undergraduate/202/fall04/Projects/CommonErrors.shtml in the Type1 class is an object of Type2, similarly declared in the file type2.h and defined in the file type2.cpp. main.cpp #include
suggestions for errors that should be included in this document or have questions or suggestions for improving the document please email Mr. Frey Definitions Commonly used words and phrases found in the compiler and linker error messages. identifier -- the name of a class, struct, function or variable collect2: ld returned 1 exit status -- usually found as the last line of the error. This phrase indicates that you have a linker (ld) error, not a compiler error. Linker errors occur when g++ tries to combine all of your .o files into an executable file. Linker errors CANNOT be fixed by guarding header files or by changing which header files are included in your .cpp file. non-aggregate type -- classes and structs are generically called "aggregate" types. If you get an error indicating that your class is a "non-aggregate type", then the compiler has not seen your class definition and doesn't recognize your class as such. read-only structrure -- refers to a const object. This phrase is generally found in a compiler error when you are trying to change a data member in a const object. Compiler Errors undeclared identifier Example doy.cpp: In function `int main()': doy.cpp:25: `DayOfYear' undeclared (first use this function) doy.cpp:25: (Each undeclared identifier is reported only once for each function it appears in.) doy.cpp:25: parse error before `;' token Meaning You used "DayOfYear" in your code, but the compiler has not seen a definition for "DayOfYear". It doesn't know what "DayOfYear" is. Usual Causes You forgot to include the header file that defines the class/struct/function/etc You misspelled the name of the identifier cout undeclared Example xyz.cpp: In function `int main()': xyz.cpp:6: `cout' undeclared (first use this function) xyz.cpp:6: (Each undeclared identifier is reported only once for each function it appears in.) Meaning This is really a special case of "undeclared identifier". Usual causes You forgot to include