Compiler Error C2017

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at Compiler Error C2017.

illegal escape sequence

An escape sequence, such as \t, appears outside of a character or string constant.

The following sample generates C2017:

// C2017.cpp  
int main() {  
   char test1='a'\n;   // C2017  
   char test2='a\n';   // ok  
}  

C2017 can occur when the stringize operator is used with strings that include escape sequences.

The following sample generates C2017:

// C2017b.cpp  
#define TestDfn(x) AfxMessageBox(#x)  
TestDfn(CString("\\") + CString(".h\"\n\n"));   // C2017