Why isn't it possible to access a javascript function by its original name once it is assigned to a different var?

Question

var f=function foo()
{
console.log("hello");
};

f();
foo();

This produces an error as : "Exception: ReferenceError: foo is not defined"

But "foo" is defined. Why does this happen?I know that this is a function expression and "f()" is used to access this function. But this is not an anonymous function , I do have a name for this function. Why am I not able to access the function using its name?

Answer 1

MDN - function expression

syntax

var myFunction = function [name]([param1[, param2[, ..., paramN]]]) {
   statements
};

The function name. Can be omitted, in which case the function is anonymous. The name is only local to the function body.

Answer 2

You are conflating function expressions with function declarations .

This declares a variable foo and assigns an anonymous function to it:

var foo = function() {};

This declares a function bar in the current scope:

function bar() {};

This declares a variable baz and assigns it a function whose name is qux :

var baz = function qux() {};

Note that in this case, the function is not being declared in this scope. Only the variable is being declared. It just so happens that the name property of this function will be set to qux .

See this question .

Edit: code blocks Edit: added relevant link