Compiler Error C2143

syntax error : missing 'token1' before 'token2'

A syntax error is an error in the use of the language. A token is a language element such as a keyword or operator. Roughly translated, anything that is not whitespace (spaces, tabs, line feeds, comments, and so on) is a token.

The compiler expects certain language elements to appear before or after other elements. For instance, an if statement requires that the first non-whitespace character following the word if must be an opening parenthesis. If anything else is used, the compiler cannot “understand” the statement. For example:

if j < 25    // syntax error : missing '(' before 'j'

This error can also be caused by a missing closing brace ‘}’, right parenthesis ‘)’, or semicolon ‘;’. The missing token may belong on the line above where the error was actually detected and reported.

This error can also be caused by an invalid tag in a class declaration. The following are examples of these errors:

class X
{
   int member
} x;          // error, missing ; on previous line
class + {};   // error, + is an invalid tag name

This error can also be caused by placing a label by itself without being attached to a statement. If you need to place a label by itself, for example at the end of a compound statement, it can be attached to a null statement.

The following is an example of this error:

void func1()
{
   end:      // error
}            // this line is not a statement
void func2()
{
   end:      // OK
    ;        // this label attached to null statement
}

This error can also be caused when the ANSI compatibility option (/Za) is in effect and the source code contains single line comments.

The following is an example of this error:

int i;    // syntax error : missing ';' before 'division operator'
int j;    /* no error */

In the first case, the first single line comment character, ‘/’, is interpreted as a division operator since single line comments are not valid according to the ANSI C language standard. However, single line comments are legal in the C++ language.

Tips

• Check the C/C++ Language Quick Reference to determine where the code is syntactically incorrect.
  
  
• Since this error is sometimes detected after the line where the error actually occurred, check a few lines up in the code for the syntax error.
  
  
• Do not use the /Za compiler switch if you want to use single line comments in a C language file.