Posted on Jul 6, 2020 • Edited on Aug 24, 2020

Null vs Undefined? Answer: Nil

In JS I don't think in terms of null or undefined, but think in terms of "nil".
I use a utility func similar to Ramda's R.isNil

And I have a complement func called, isNotNil

/** @func true if var is null or undefined @param {*} v @return {boolean} */ export const isNil = v => v === undefined || v === null;

/** @func complement @param {*} v @return {boolean} */ export const isNotNil = v => !isNil(v);

//@tests const aTrue = [undefined, null, (() => undefined)(), (() => null)(), (() => console.log())()]; const aFalse = ["", 0, -0, [], {}, () => undefined, "undefined", "null", NaN, -Infinity, 9e9999, 9999n]; logForeachParam(isNil, aTrue); logForeachParam(isNil, aFalse);