المعرفة:: JavaScript الحالة::مؤرشفة المراجع:: The Complete JavaScript Course 2022 From Zero to Expert
IIFE
- Sometimes in JavaScript, we need a function that disappears right after it’s called once).
- This can be done by writing the function expression without assigning it to any variable then wrapping all of this into parentheses (transforming the statement into an expression).
- It’s useful for encapsulating data, since inner scope won’t be accessed by any outer one.
- This technique will be needed with
async/await.
// IIFE
// Normal function
(function () {
console.log("This will never run again");
const isPrivate = 23;
})();
// Arrow function
(() => console.log("This will ALSO never run again"))();- In modern JavaScript IIFE is not used widely because blocks can be used for achieving the same behavior with variables.
{
const isPrivate = 23;
var notPrivate = 46;
}
// console.log(isPrivate); // Can't be accessed
console.log(notPrivate); // Can be accessed