shonnly

var obj = {};
obj[Symbol.iterator] = function* () {yield 'Hatfield', yield 'Ulrich', yield 'Hammet'};
console.log(...obj); // Hatfield Ulrich Hammet

shonnly

var obj = {};
obj[Symbol.for('name')] = 'Jordan';

console.log(obj); // {Symbol(name): "Jordan"}

obj[Symbol.for('name')] = 'Jordan'; // Idempotent? Yes.

console.log(obj); // {Symbol(name): "Jordan"}

shonnly

var obj = {};
obj[Symbol('name')] = 'Jordan';

console.log(obj); // {Symbol(name): "Jordan"}

obj[Symbol('name')] = 'Jordan'; // Idempotent?

console.log(obj); // {Symbol(name): "Jordan", Symbol(name): "Jordan"}

shonnly

var s1 = Symbol('foo'); // local symbol for 'foo'
var s2 = Symbol.for('foo'); // global symbol for 'foo'

s1 === s2 // false

shonnly

var s1 = Symbol.for('s'); // creates a unique Global Symbol
var s2 = Symbol.for('s'); // fetches existing Global Symbol

s1 === s2 // true

shonnly

var s1 = Symbol('s'); // creates a unique local Symbol (not Global)
var s2 = Symbol.for('s'); // creates Global Symbol instance accessible from anywhere at runtime

s1 === s2 // false

shonnly

var s = Symbol.for('random_string')
console.log(s); // Symbol(random_string)

shonnly

var s = Symbol('foo');
Symbol.for('foo'); // Symbol(foo)

shonnly

var s = Symbol('foo');
alert(s); // Uncaught TypeError: Cannot convert a Symbol value to a string

// use alert(s.toString()) or alert(s.description) instead

shonnly

var s = Symbol('foo');
alert(s); // Uncaught TypeError: Cannot convert a Symbol value to a string