Creating a Reusable Module
Now that we have working functions, let's create a reusable JavaScript module file that we can import into other projects.
First, let's exit the Node.js interactive shell by pressing Ctrl+C twice or typing .exit and pressing Enter.
Now, create a new file named object-utils.js in the project directory:
- In the WebIDE, navigate to the file explorer panel on the left
- Right-click in the project directory and select "New File"
- Name the file
object-utils.js
- Add the following code to the file:
/**
* Converts all keys of an object to lowercase
* @param {Object} obj - The input object
* @returns {Object} A new object with all keys in lowercase
*/
const lowerizeKeys = (obj) => {
return Object.keys(obj).reduce((acc, key) => {
acc[key.toLowerCase()] = obj[key];
return acc;
}, {});
};
/**
* Recursively converts all keys of an object and its nested objects to lowercase
* @param {Object} obj - The input object
* @returns {Object} A new object with all keys in lowercase (including nested objects)
*/
const deepLowerizeKeys = (obj) => {
return Object.keys(obj).reduce((acc, key) => {
const value = obj[key];
// Check if the value is an object and not null
const newValue =
value && typeof value === "object" && !Array.isArray(value)
? deepLowerizeKeys(value)
: value;
acc[key.toLowerCase()] = newValue;
return acc;
}, {});
};
// Export the functions
module.exports = {
lowerizeKeys,
deepLowerizeKeys
};
Now, let's create a test file to verify that our module works correctly. Create a new file named test.js:
- In the WebIDE, navigate to the file explorer panel on the left
- Right-click in the project directory and select "New File"
- Name the file
test.js
- Add the following code to the file:
// Import the functions from our module
const { lowerizeKeys, deepLowerizeKeys } = require("./object-utils");
// Test with a simple object
const user = {
Name: "John",
AGE: 30,
Email: "john@example.com"
};
console.log("Original object:");
console.log(user);
console.log("\nObject with lowercase keys:");
console.log(lowerizeKeys(user));
// Test with a nested object
const nestedObject = {
User: {
Name: "John",
Contact: {
EMAIL: "john@example.com",
PHONE: "123-456-7890"
}
}
};
console.log("\nNested object:");
console.log(nestedObject);
console.log("\nNested object with lowercase keys (shallow):");
console.log(lowerizeKeys(nestedObject));
console.log("\nNested object with lowercase keys (deep):");
console.log(deepLowerizeKeys(nestedObject));
Now, let's run the test file:
node test.js
You should see output similar to:
Original object:
{ Name: 'John', AGE: 30, Email: 'john@example.com' }
Object with lowercase keys:
{ name: 'John', age: 30, email: 'john@example.com' }
Nested object:
{
User: {
Name: 'John',
Contact: { EMAIL: 'john@example.com', PHONE: '123-456-7890' }
}
}
Nested object with lowercase keys (shallow):
{
user: {
Name: 'John',
Contact: { EMAIL: 'john@example.com', PHONE: '123-456-7890' }
}
}
Nested object with lowercase keys (deep):
{
user: {
name: 'John',
contact: { email: 'john@example.com', phone: '123-456-7890' }
}
}
Congratulations! You've successfully created a reusable JavaScript module with functions to convert object keys to lowercase. This module can now be imported into any of your JavaScript projects.
