CODEWITHSUNDEEP
javascriptecmascript-6
Kirk Strobeck
Kirk Strobeck

Reputation: 18559

Method destructuring not working

Trying to determine why this wont function properly.

// assuming this works
const { emitter } = window.project;
emitter.emit('foo');

// why doesnt this
const { emitter: { emit } } = window.project;
emit('foo');

Upvotes: 0

Views: 134

Answers (1)

Felix Kling
Felix Kling

Reputation: 816322

Presumably because the emit method depends on this referring to a specific value. The value of this depends on how a function is called (if it's an unbound, non-arrow function), and you are calling the function in two different ways:

  • emitter.emit() will cause this inside emit to refer to emitter
  • emit() will cause this to refer to undefined (strict mode) or the global object (non-strict mode)

That has nothing to do with ES6 specifically.

More information about this: You Don't Know JS: this & Object Prototypes.

Upvotes: 3

Related Questions