JavaScript: Create an object with keys generated by running the provided function for each key and the same values as the provided object

JavaScript fundamental (ES6 Syntax): Exercise-81 with Solution

Create Keys with Function for Object

Write a JavaScript program to create an object with keys generated by running the provided function for each key. The object will have the same values as the provided object.

• Use Object.keys() to iterate over the object's keys.
• Use Array.prototype.reduce() to create a new object with the same values and mapped keys using fn.

Sample Solution:

JavaScript Code:

//#Source https://bit.ly/2neWfJ2
// Define the function 'mapKeys' to map the keys of an object using a given function.
const mapKeys = (obj, fn) =>
  // Reduce the keys of the object to a new object, applying the function to each key and assigning the original value.
  Object.keys(obj).reduce((acc, k) => {
    // Assign the value of the original key to the new key generated by applying the function.
    acc[fn(obj[k], k, obj)] = obj[k];
    return acc;
  }, {});

// Example usage:
console.log(mapKeys({ a: 1, b: 2 }, (val, key) => key + val)); // Outputs: { 'a1': 1, 'b2': 2 }

Output:

{"a1":1,"b2":2}

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-81-1 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript program that generates new keys for an object by applying a function to each original key.
• Write a JavaScript function that transforms an object’s keys using a provided callback and returns the new object with same values.
• Write a JavaScript program that maps over an object’s keys, modifies them, and constructs a new object with the transformed keys.

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