JSFiddle - React, Tailwind, and code Playground

JavaScript

var arr = [];

//name property will be
function a() {}

//name property will be b
var b = function() {}

//name property will be ab
var c = ab = function() {} 

//name property will be an emty string
var d = arr[0] = function() {}
 
document.write(a.name + '<br>');
document.write(b.name + '<br>');
document.write(c.name + '<br>');
document.write(d.name === '' ? 'empty' : 'some other value' + '<br>');