This JavaScript exception missing formal parameter occurs if any function declaration doesn’t have the valid parameters.
Message:
SyntaxError: missing formal parameter (Firefox)
Error Type:
SyntaxError
Cause of Error: The function declaration is missing the formal parameters.
Example 1: In this example, the parameter ‘num’ is not defined in the list of formal parameters, So the error has occurred.
HTML
<!DOCTYPE html> <html> <head> <title>Syntax Error</title> </head> <body> <script> function cube(5) { return num * num * num; } </script> </body> </html> |
Output(In Firefox console):
SyntaxError: missing formal parameter
Example 2: In this example, the parameter ‘neveropen’ is not defined in a list of formal parameters, So the error has occurred.
HTML
<!DOCTYPE html> <html> <head> <title>Syntax Error</title> </head> <body> <script> function GFG("Geek") { return GeeksForGeeks; }; </script> </body> </html> |
Output(In Firefox console):
SyntaxError: missing formal parameter
