How to Clear an Object in JavaScript

Clear an Object in JavaScript #

Use a for..in loop to clear an object and delete all its properties. The loop will iterate over all the enumerable properties in the object. On each iteration, use the delete operator to delete the current property.

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const obj = {a: 'one', b: 'two'};

for (const key in obj) {
  delete obj[key];
}

console.log(obj); // 👉️ {}

The for...in loop iterates over all of an object's enumerable properties.

Properties assigned to the object using the Object.definedProperty method are non-enumerable by default and are not iterated over in a for...in loop.

The Object.defineProperty method is mostly used by 3rd party library creators and not in day-to-day code, so chances are the for...in loop covers all of your object's properties.

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let obj = {a: 'one', b: 'two'};

obj = {};

console.log(obj); // 👉️ {}

Notice that we used the let keyword when declaring the obj variable.

In the extremely unlikely scenario that your object contains non-enumerable properties, you can use the following approach to clear an object.

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let obj = {a: 'one', b: 'two'};

Object.defineProperty(obj, 'color', {
  value: 'red',
  enumerable: false, // 👈️ defaults to false
  configurable: true,
});

const allProperties = Object.getOwnPropertyNames(obj);
console.log(allProperties); // 👉️ ['a', 'b', 'color']

allProperties.forEach(property => {
  delete obj[property];
});

console.log(Object.getOwnPropertyNames(obj)); // []

We used the Object.getOwnPropertyNames method to get an array of the enumerable and non-enumerable properties of the object.

We used the Array.forEach method to iterate over the array and cleared each property using the delete operator.

Further Reading #

• Remove Null Values from an Object in Javascript
• Remove all Undefined Values from an Object in JavaScript
• Remove Object from an Array by its Value in JavaScript
• Remove the Falsy values from an Object in JavaScript
• Remove Property from all Objects in Array in JavaScript
• How to Rename an Object's Key in JavaScript
• Check if a Value is an Object using JavaScript