在 IIFE 内部调用 function

Question

 let f = function(x) { alert(x) } (function() { f(1) }())

Why is this code throwing an error? At first, I thought the problem was connected with the incorrect syntax of the IIFE but then I learned that this syntax is also appropriate

Answer 1

This is the one of the rare cases where a semicolon is necessary to separate the function expression from the calling with the following parentheses.

 let f = function(x) { alert(x) }; // <------------------- (function() { f(1) }())