JSFiddle - React, Tailwind, and code Playground

JavaScript

function func1(obj) {
    obj.a = 5;
    obj.b = 6;
}

function main() {
    var vars = {
        a: null,
        b: null,
        c: null
    };
    with(vars) {
        a = 'test';
        c = 222;
        console.log(vars);
        func1(vars);
        console.log(vars);
    }
}

main();