函数上的额外括号
it1352
帮助1人
问题说明
我遇到类似这样的标记：
I encountered markup similar to this:
var something = (function(){
//do stuff
return stuff;
})()
document.ondblclick = function(e) { alert(something(e)) };
我不明白开头（并在 something 变量中关闭）（）。
I don't understand the opening ( and closing )() in the something variable. Could you explain the difference to writing it like this?
var something = function(){
//do stuff
return stuff;
};
$ b
谢谢！
Thanks!
正确答案
#1
这可能更容易理解，如果你离开冗余的括号，因为他们没有目的：
It's probably easier to understand if you leave the redundant parens out because they serve no purpose:
var something = function() {
return 3;
} // <-- a function.
(); // now invoke it and the result is 3 (because the return value is 3) assigned to variable called something
console.log(something) //3 because the function returned 3
var something = function() {
return 3;
}; // a function is assigned to a variable called something
console.log(something) //logs the function body because it was assigned to a function
console.log(something()) //invoke the function assigned to something, resulting in 3 being logged to the console because that's what the function returns
这篇好文章是转载于：学新通技术网
