Javascript 101-传递给函数的类型转换变量

Question

Hopefully a basic question, but is it all possible to typecast varibles when you define a function in JS? this would be useful when constructing a library for use by other developers.

functionName:function(var1:string, var2:int)

instead of

functionName:function(var1, var2)

Answer 1

No, this is not possible in normal Javascript. Javascript is a completely dynamically-typed language. Types of variables are only known at runtime. So all you can do is throw an exception when you get a wrong type.

There are, however, Javascript dialects like TypeScript or Dart which do have types and compile to normal Javascript.