javascript - Why is the parenthesis missing in this anonymous function call? -

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• what difference between 2 declarations of module in javascript? 3 answers

i reading book , has code example

function getfunction() {     var result = [];     (var = 0; < 10; i++) {         result[i] = function(num) {             return function() {                 console.log("this " + num);             }         }(i);     };      return result; } 

it working ok why anonymous function here not wrapped in parenthesis (function(...))(i); ? , in cases can parenthesis omitted in anonymous function?

since syntax function declarations , function expressions identical, js tells 1 using code around function.

to stop being function declaration need use in expression. wrapping in parenthesis will preceding = (as host of other operators). since there = here, parenthesis unnecessary.