JSFiddle - React, Tailwind, and code Playground

JavaScript

const falsy = false;
const emptyString = '';
const nullish = null;
const uDefined = undefined;

console.log('1', falsy ?? 'Some string');
console.log('2', emptyString ?? 'Default string') //"" (as the empty string is not null or undefined)
console.log('3', nullish ?? 'Default string')
console.log('4', uDefined ?? 'Default string')


console.log('-------');

console.log('1.1', falsy || 'Some string');
console.log('2.2', emptyString || 'Default string')
console.log('3.3', nullish || 'Default string')
console.log('4.4', uDefined || 'Default string')