JSFiddle - React, Tailwind, and code Playground
JavaScript
//Case 1 :
//Options is undefined
var options;
var size = options && options.size || 10;
alert(size);
//Case 2 :
//Options is object but doesnt have size as its property
var options = {};
var size = options && options.size || 10;
alert(size);
//Case 3 :
//Options is object and have size as its property
var options = { size : 20};
var size = options && options.size || 10;
alert(size);