JavaScript - use throw keyword with Nullish Coalescing Operator (??) when value is null or undefined

In this short article we would like to show how to use throw keyword with Nullish Coalescing Operator (??) when value is null or undefined in JavaScript.

In 2024, JavaScript syntax doesn't let to use throw keyword with Coalescing Operator (??), so it is necessary to use some tricks.

Quick solution:

const throwError = (message) => {
    throw new Error(message);
};


// Usage example:

const object = ...

const item = object.item ?? throwError('Value is not available.');  // <----- the solution

Practical example

// ONLINE-RUNNER:browser;

const throwError = (message) => {
    throw new Error(message);
};


// Usage example:

const object = {
    a: false,
    b: 0,
    c: 'Text here ...',
    d: null,
    e: undefined
};

const a = object.a ?? throwError('`object.a` value is not available.');
const b = object.b ?? throwError('`object.b` value is not available.');
const c = object.c ?? throwError('`object.c` value is not available.');
const d = object.d ?? throwError('`object.d` value is not available.');  // it throws exception
const e = object.e ?? throwError('`object.e` value is not available.');  // it throws exception