JSFiddle - React, Tailwind, and code Playground

JavaScript

var var4 = {
    proper1: 'a'
};

function fun3(var4) {
    var4 = {
        proper1: 'b',
        proper2: 'w'
    };
    console.log(var4.proper1);
    console.log(var4.proper2);
}

fun3(var4);

console.log(var4.proper1);
console.log(var4.proper2);