JavaScript: Create a function that invokes the method at a given key of an object
JavaScript fundamental (ES6 Syntax): Exercise-60 with Solution
Write a JavaScript program to create a function that invokes the method at a given key of an object. Optionally, add any parameters that are supplied 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.
Sample Solution:
JavaScript Code:
//#Source https://bit.ly/2neWfJ2
const bindKey = (context, fn, ...args) =>
function() {
return context[fn].apply(context, args.concat(...arguments));
};
const freddy = {
user: 'fred',
greet: function(greeting, punctuation) {
return greeting + ' ' + this.user + punctuation;
}
};
const freddyBound = bindKey(freddy, 'greet');
console.log(freddyBound('hi', '!'));
Sample Output:
hi fred!
Flowchart:

Live Demo:
See the Pen javascript-basic-exercise-60-1 by w3resource (@w3resource) on CodePen.
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