# Error usage,

# Error usage,
# The error command is one of the pre-processing commands in the C/C ++ language. When the pre-processor pre-processes to the # error command, it stops compiling and outputs custom error messages. Syntax:# Error [custom error messages]Note: The square brackets "[]" in the preceding syntax can indicate that custom error messages can be omitted without being written. Example 1:

# Error Sorry, an error has occurred!

Example 2:

 

1 # example of error 2: 3/* 4 * check whether the compiler for compiling this source file is a C ++ compiler 5 * If the C language compiler is used, execute # error Command 6 * If the C ++ compiler is used skip # error command 7 */8 # ifndef _ cplusplus 9 # error, you are not using the C ++ compiler! 10 # endif11 # include <stdio. h> 12 int main () 13 {14 printf ("Hello, World! "); 15 return 0; 16}