JavaScript exception mechanism

1. JavaScript has only one exception class error, no need to declare the exception when defining the function, so there is no throws keyword

2. JavaScript is a weakly typed language, so exception instances in parentheses after a catch statement do not need to declare a type

3. JavaScript has only one exception class, so there can be at most one catch block after the try block

4. Getting the description of the exception is through the message property of the exception object, not through the GetMessage () method

JavaScript exception mechanism