JavaScript: Create an object composed of the properties the given function returns falsey for

JavaScript: Exercise-154 with Solution

Write a JavaScript program to create an object composed of the properties the given function returns false for. The function is invoked with two arguments: (value and key).

• Use Object.keys() and Array.prototype.filter() to remove the keys for which fn returns a truthy value.
• Use Array.prototype.reduce() to convert the filtered keys back to an object with the corresponding key-value pairs.
• The callback function is invoked with two arguments: (value, key).

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
const omitBy = (obj, fn) =>
  Object.keys(obj)
    .filter(k => !fn(obj[k], k))
    .reduce((acc, key) => ((acc[key] = obj[key]), acc), {});

console.log(omitBy({ a: 1, b: '2', c: 3 }, x => typeof x === 'number'));

Sample Output:

{"b":"2"}

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-154-1 by w3resource (@w3resource) on CodePen.

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