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delegate.js
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delegate.js
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// Write a delegate function that can be used to delegate the behavior of a method or function
// to another object's method. delegate takes a minimum of two arguments: (1) the object and
// (2) name of the method on the object. The remaining arguments, if any, are passed —
// as arguments — to the objects' method that it delegates to.
// Note that this is not the same as using bind. bind returns a new function, whereas delegate
// maintains the reference.
// Here's a sample run;
function delegate(obj, methodName, ...args) {
return function () {
return obj[methodName].apply(obj, args);
};
}
const foo = {
name: 'test',
bar(greeting) {
console.log(`${greeting} ${this.name}`);
},
};
const baz = {
qux: delegate(foo, 'bar', 'hello'),
};
console.log(baz.qux()); // logs 'hello test';
foo.bar = () => { console.log('changed'); };
console.log(baz.qux()); // logs 'changed'