JavaScript: Create a new object from the specified object, where all the keys are in lowercase

JavaScript fundamental (ES6 Syntax): Exercise-180 with Solution

Object with Lowercase Keys

Write a JavaScript program to create an object from the specified object, where all keys are in lowercase.

• Use Object.keys() and Array.prototype.reduce() to create a new object from the specified object.
• Convert each key in the original object to lowercase, using String.prototype.toLowerCase().

Sample Solution:

JavaScript Code:

// Define a function 'lowercaseKeys' that takes an object 'obj' as input
const lowercaseKeys = obj =>
  // Use 'reduce' to iterate over the keys of the object and create a new object with lowercase keys
  Object.keys(obj).reduce((acc, key) => {
    // Set the key in the new object to lowercase and assign the corresponding value from the original object
    acc[key.toLowerCase()] = obj[key];
    // Return the updated accumulator object
    return acc;
  }, {});

// Define an object 'myObj' with keys in mixed case
const myObj = { Name: 'Adam', sUrnAME: 'Smith' };
// Call 'lowercaseKeys' function with 'myObj' and assign the result to 'myObjLower'
const myObjLower = lowercaseKeys(myObj);
// Print the resulting object with lowercase keys
console.log(myObjLower);

Output:

{"name":"Adam","surname":"Smith"}

Visual Presentation:

Flowchart:

Live Demo:

See the Pen javascript-basic-exercise-180-1 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript program that converts all keys of an object to lowercase and returns a new object with unchanged values.
• Write a JavaScript function that iterates over an object and constructs a new object with each key transformed to lowercase.
• Write a JavaScript program that deep clones an object while converting all nested keys to lowercase.
• Write a JavaScript function that checks an object’s keys and outputs a version with all keys normalized to lowercase.

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