javascript - What are the differences between these three types of module pattern?

Question

1)function () { 
    // code here...

}();

2)(function () { 
    // code here...

})();



3)(function () { 
    // code here...

}());

What are the differences (especially third variant)? Are they all the same?

Answer 1

2 and 3 are exactly equivalent. There is no functional difference between them.

1 is a syntax error. Because the function is not wrapped in brackets, it is treated as a function declaration. It is invalid because function declaration need to be named. The brackets make it a "function expression"; these do not need to be named.