How to remove all null and undefined properties from an object in JavaScript

In this Article we will go through how to remove all null and undefined properties from an object only using single line of code in JavaScript. This is a one-line JavaScript code snippet that uses one of the most popular ES6 features => Arrow Function.

Let's define this short function:

const removeNullUndefined = obj => Object.entries(obj).reduce((a, [k, v]) => (v == null ? a : (a[k] = v, a)), {});

const removeNullUndefined = obj => Object.entries(obj).filter(([_, v]) => v != null).reduce((acc, [k, v]) => ({ ...acc, [k]: v }), {});

const removeNullUndefined = obj => Object.fromEntries(Object.entries(obj).filter(([_, v]) => v != null));

removeNullUndefined({
    foo: null,
    bar: undefined,
    fuzz: 42,
});                         // { fuzz: 42 }