Correct: `Array.from()` (it’s a static method) Incorrect: `Array.join()` (doesn’t exist; it’s a prototype method) This patch uses the common `#` syntax to denote `.prototype.`.
735 B
735 B
bindKey
Creates a function that invokes the method at a given key of an object, optionally adding any additional supplied parameters to the beginning of the arguments.
Return a function that uses Function.prototype.apply() to bind context[fn] to context.
Use the spread operator (...) to prepend any additional supplied parameters to the arguments.
const bindKey = (context, fn, ...boundArgs) => (...args) =>
context[fn].apply(context, [...boundArgs, ...args]);
const freddy = {
user: 'fred',
greet: function(greeting, punctuation) {
return greeting + ' ' + this.user + punctuation;
}
};
const freddyBound = bindKey(freddy, 'greet');
console.log(freddyBound('hi', '!')); // 'hi fred!'