How to Delete an Object Property vs Assigning it to Undefined in JavaScript?

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In JavaScript, you can remove an object property by either assigning it to undefined or by using the delete keyword.

Here’s an example of how to delete an object property using the delete keyword:

const myObj = {
  prop1: "value1",
  prop2: "value2"
};

delete myObj.prop1;

In this example, we have an object myObj with two properties. We use the delete keyword to remove the prop1 property from the object.

And here’s an example of how to delete an object property by assigning it to undefined:

const myObj = {
  prop1: "value1",
  prop2: "value2"
};

myObj.prop1 = undefined;

In this example, we have the same object myObj, and we set the value of the prop1 property to undefined. This effectively removes the value of the property from the object, but the property itself still exists.

When deciding whether to use the delete keyword or assign undefined to a property, it’s important to consider the implications of each approach.

If you use the delete keyword, the property is completely removed from the object and any references to that property will return undefined. This can be useful if you want to free up memory and completely remove the property from the object.

On the other hand, if you assign undefined to a property, the property still exists, but its value is undefined. This can be useful if you want to preserve the property for later use, but temporarily remove its value.

In general, it’s recommended to use the delete keyword to remove object properties when you don’t need them anymore, and assign undefined to a property only if you need to preserve the property for later use.

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