Is there a purpose to hoisting variables?

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“Hoisting” is necessary for mutually recursive functions (and everything else that uses variable references in a circular manner):

function even(n) { return n == 0 || !odd(n-1); }
function odd(n) { return !even(n-1); }

Without “hoisting”, the odd function would not be in scope for the even function. Languages that don’t support it require forward declarations instead, which don’t fit into JavaScripts language design.

Situations that require them might arise more often that you’d think:

const a = {
    start(button) {
        …
        button.onclick = e => {
            …
            b.start(button);
        };
    }
};
const b = {
    start(button) {
        …
        button.onclick = e => {
            …
            a.start(button);
        };
    }
};

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