How to create a new object from the specified object, where all the keys are in lowercase in JavaScript?

0 0 1 minute read

In this article, we will learn how to make a new object from the specified object where all the keys are in lowercase using JavaScript.

Example: Here, we have converted the upper case to lower case key values.

Input: {RollNo : 1, Mark : 78}

Output: {rollno : 1, mark : 78}

Approach 1: A simple approach is to Extract keys from Object and LowerCase to all keys and make Object with them. For this purpose we use Object.keys( ) to extract keys from the object. And use String.toLowerCase() method to lower case keys and Array.reduce() method to make an object with lower-case strings.

Example: This example shows the above-explained approach.

Javascript

// Test Object 
const Student = { RollNo : 1, Mark: 78 }; 
  
// Function to lowercase keys  
function Conv( obj , key ) 
{ 
  obj[key.toLowerCase()] = Student[key]; 
  return Student; 
} 
  
// Function to  create object from lowercase keys  
function ObjKeys( obj) { 
  let arr1 = Object.keys(obj); 
  let ans = {}; 
  for(let i of arr1) 
  { 
  Conv(ans,i); 
  
  } 
  return ans; 
} 
  
a = ObjKeys(Student); 
console.log(a);

Output:

{ rollno : 1, mark : 78}

Approach 2: The simplest approach is to convert the Object to an array and make keys lowercase and make objects from a new array. For this purpose, we use Object.entries() to make an array from Object. And we use Array.map() to apply String.toLowerCase() method to all keys. To convert a new array to an Object we use Object.fromEntries().

Example: This example shows the above-explained approach.

Javascript

// Test Object 
const employ = { EmpId: 101, Batch: 56 }; 
  
// Converting Object to array  
let k = Object.entries(employ); 
  
//  Apply toLowerCase function to all keys  
let l = k.map(function(t){ 
  t[0] = t[0].toLowerCase() 
  return t; 
  } 
); 
  
// Converting back array to Object 
const a  = Object.fromEntries(l) 
console.log(a)

Output:

{ empid : 101, batch : 56 }

Whether you’re preparing for your first job interview or aiming to upskill in this ever-evolving tech landscape, zambiatek Courses are your key to success. We provide top-quality content at affordable prices, all geared towards accelerating your growth in a time-bound manner. Join the millions we’ve already empowered, and we’re here to do the same for you. Don’t miss out – check it out now!