async function
objects created with the AsyncFunction
constructor are parsed when the function is created. This is less efficient than declaring an async function with an async function expression
and calling it within your code, because such functions are parsed with the rest of the code.
All arguments passed to the function are treated as the names of the identifiers of the parameters in the function to be created, in the order in which they are passed.
Note: async functions created with the AsyncFunction
constructor do not create closures to their creation contexts; they are always created in the global scope.
When running them, they will only be able to access their own local variables and global ones, not the ones from the scope in which the AsyncFunction
constructor was called.
This is different from using eval
with code for an async function expression.
Invoking the AsyncFunction
constructor as a function (without using the new
operator) has the same effect as invoking it as a constructor.