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Should the following code work?
if(true) {
async function bar() {
console.log("hello");
}
}
bar();
Chrome 80 and Firefox 72 both throw a ReferenceError saying bar is not defined. So it seems like async function bar() {...} declarations are block scoped whereas function bar() {...} declarations are function scoped? Confusing if that's the case, but can someone just confirm that for me with a link to the relevant part of the spec?
Also, is there a way to make an async function declaration function-scoped when declared from within a block?
986
Function scoped variables: A function scoped variable means that the variable defined within a function will not accessible from outside the function. Block scoped variables: A block scoped variable means that the variable defined within a block will not be accessible from outside the block.
Variables declared with the var keyword can NOT have block scope. Variables declared inside a { } block can be accessed from outside the block.
Block Level Scope: This scope restricts the variable that is declared inside a specific block, from access by the outside of the block. The let & const keyword facilitates the variables to be block scoped.
Block scoping means declaring a variable, not just inside a function, but around any curly brackets like if statements or loops. The variable itself let i is still in memory, but the engine just won't allow you to access it like before when we used var.
It seems like
async function bar() {...}declarations are block scoped
Yes, just like normal. Function declarations are block-scoped in general.
… whereas
function bar() {...}declarations are function scoped?
Not really, except in sloppy mode for legacy reasons. This does not affect async function and function* declarations, which don't need any backwards-compatibility.
137
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