Purpose of Object()()

Question

I have been looking through various JS code. 
Specifically looking at WooCommerce Booking Availability JS file (just as an example for using ()()) - I have noticed they use Object()():
Here is a code snippet:
``` 
var e = Object.create(null);
var a = function () {
    return Object(e.createElement)(n.Icon, {
      icon: Object(e.createElement)("svg", {
        xmlns: "http://www.w3.org/2000/svg",
        width: "24",
        height: "24",
        viewBox: "0 0 24 24"
      }, Object(e.createElement)("path", {
        d: "M19 5v14H5V5h14m1.1-2H3.9c-.5 0-.9.4-.9.9v16.2c0 .4.4.9.9.9h16.2c.4 0 .9-.5.9-.9V3.9c0-.5-.5-.9-.9-.9zM11 7h6v2h-6V7zm0 4h6v2h-6v-2zm0 4h6v2h-6zM7 7h2v2H7zm0 4h2v2H7zm0 4h2v2H7z"
      }), Object(e.createElement)("path", {
        fill: "none",
        d: "M0 0h24v24H0z"
      }))
    })
  }
```
the line to look at is return Object(...)(...).
I know that using ()() calls function that returns a function and that the second () is to call the returned function. Such as:

var doubleP = function(x){
    return function(y, z){
        console.log(x, y, z);
    }
}
doubleP('x')("y", "z");

Is this all that the above code is doing? 
Or is there another technique available for the Object Constructor?

Justin Horner · Accepted Answer

Hello, William
I've never worked with WooCommerce, so I'm not familiar with the codebase, but I believe you're right. The code is simply referencing a function first using Object() and then calling it passing arguments needed.
When you call Object and pass a function, you can then immediately invoke that function by using the second set of parentheses, like this.
```javascript
function add(num1, num2) {
     return num1 + num2;
}
var result = Object(add)(5, 7);
console.log(result); // 12
```
I hope this helps.
Happy coding 🙂

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William Hurst

William Hurst

Purpose of Object()()

1 Answer

Justin Horner

Justin Horner