JSFiddle - React, Tailwind, and code Playground

JavaScript

var MODULE = MODULE || {};

    MODULE.Submodule = (function(){
    var foo = [],
        bar = [];

    var init = function() {
        foo = ['a','b','c']; // This doesn't set MODULE.Submodule.foo
        bar.push('a'); // But this works as expected
        
        console.log('foo: ' + MODULE.Submodule.foo()); // foo:
        console.log('bar: ' + MODULE.Submodule.bar()); // bar: a
    }
    
    var modify = function()
    {
        foo = [];
        foo.push("test");
    }
    
    return {
        init: init,
        modifyArrays: modify,
        foo: function() { return foo; },
        bar: function() { return bar; }
    }
    }());

    MODULE.Submodule.init();
    MODULE.Submodule.modifyArrays();
    console.log(MODULE.Submodule.foo());