Does anyone know how to write an immediate function using ES6 arrow syntax?
Here's the ES3/5 way of doing it:
(function () {
//...
}());
I've tried the following but get an unexpected token error on the last line.
(() => {
//...
}());
You can test this here: http://www.es6fiddle.net/hsb8bgu4/
From the Arrow functions examples,
(() => "foobar")() // returns "foobar"
So, the function invocation operator should be outside.
(() => {
//...
})();
Here is my demo codes!
Always remember that
function_name+()===function_caller
/* ES5 */
// normal function
function abc(){
console.log(`Hello, ES5's function!`);
}
abc();
var abc = function xyz(){
console.log(`Hello, ES5's function!`);
};
abc();
// named function
var abc = function xyz(){
console.log(`Hello, ES5's function!`);
}();
// anonymous function
// 1
(function(){
console.log(`Hello, ES5's IIFE!`);
})();
// 2
(function(){
console.log(`Hello, ES5's IIFE!`);
}());
// 3
var abc = function(){
console.log(`Hello, ES5's function!`);
}();
/* ES6 */
// named arrow function
const xyz = () => {
console.log(`Hello, ES6's Arrow Function!`);
};
xyz();
const xyz = (() => {
console.log(`Hello, ES6's Arrow Function!`);
})();
// Uncaught SyntaxError: Unexpected token (
/*
const xyz = (() => {
console.log(`Hello, ES6's Arrow Function!`);
}());
*/
// anonymous arrow function
(() => {
console.log(`Hello, ES6's Arrow Function!`);
})();
Immediately-invoked function expression
let x;
(x = () => {
console.log(`ES6 ${typeof(x)}`);
})();
// ES6 function
// OR
(() => {
console.log(`ES6 ${typeof(Symbol)}`);
})();
// ES6 function
Here's a simple example.
To define an arrow function:
const temp = (x)=> {return x+" world";}
// call it as a function
temp("hello") // output: hello world
To make an arrow function immediately invoke:
const temp = ((x)=> {return x+" world";})("hello")
// use it as a variable:
console.log(temp); // output: hello world
// a self-invoking function without params:
const temp = (()=> {return "world";})()
})();es6fiddle.net/hsb8ot2mfunction_name+` ()` ===function_caller