Check if an Object is Empty in TypeScript

In TypeScript, checking if an object is empty or not can be done by checking the properties of the object. We can check for the presence of properties in the object using various built-in methods and loops. In this article, we will explore three different approaches for checking if an object is empty or not in TypeScript.

Using Object.keys() function

In this approach, we are using the Object.keys() function in TypeScript to check if an object is empty. The condition Object.keys(obj).length === 0 evaluates to true when the object (obj) has no properties, which indicates that the object is empty

Syntax:

Object.keys(obj)

Example: The below example uses Object.keys() function to check if an Object is empty in TypeScript.

Javascript

function approach1Fn(obj: Record<string, any>): boolean {
  return Object.keys(obj).length === 0;
}
const obj: Record<string, any> = {};
const res: boolean = approach1Fn(obj);
console.log(res);

Output:

true

Using for…in Loop

In this approach, we are using a for…in loop in TypeScript to iterate through the properties of the object (obj). The loop checks if any property is present, and if it is present, it returns false, indicating that the object is not empty. If no properties are found, the function returns true, indicating that the object is empty.

Syntax:

for (const variable in object) {
  // code
}

Example: The below example uses for…in Loop to check if an Object is empty in TypeScript.

Javascript

function approach2Fn(obj: Record<string, any>): boolean {
    for (const key in obj) {
        if (obj.hasOwnProperty(key)) {
            return false;
        }
    }
    return true;
}
const obj: Record<string, any> = {};
const res: boolean = approach2Fn(obj);
console.log(res);

Output:

true

Using JSON.stringify() function

In this approach, we are using the JSON.stringify() function in TypeScript to convert the object (obj) into a JSON string. The equality check JSON.stringify(obj) === ‘{}’ checks if the resulting string represents an empty object. If true, it indicates that the original object is empty, printing in the function returning true as output.

Syntax:

JSON.stringify(value, replacer?, space?)

Example: The below example uses JSON.stringify() function to check if an Object is empty in TypeScript.

Javascript

function approach3Fn(obj: Record<string, any>): boolean {
  return JSON.stringify(obj) === '{}';
}
const obj: Record<string, any> = {};
const res: boolean = approach3Fn(obj);
console.log(res);

Output:

true