Test

let  property="Miś";
const property="Kotek";

let  property="Miś";

if(property==="Miś")
{
 const property="Kotek";
}

const  property="Miś";

if(property==="Miś")
{
 property="Kotek";
}

const  property="";

if(property===null)
{
 console.log("1")
}

if(!property)
{
 console.log("2")
}

const  property="";
const  property2=0;

if(property===property2)
{
 console.log("Hello")
}

if(property==property2)
{
 console.log("World")
}

const  property="";
const  property="Ala ma kota";

let  property="";
let property="Ala ma kota";

let  property="";
property="Ala ma kota";

const  property="Miś";

if(property==="Miś")
{
  let property="Kotek";
}

let user = { name: "Ala", lastname:"Ma kota", age: 12}

for( let property in user)
{
 console.log(property)
}

let user = { name: "Ala", lastname:"Ma kota", age: 12}

for( let property in user)
{
 console.log(user[property])
}

let values = [1,2,3,4,5] 

for( let x of values)
{
 console.log(x)
}

const user = { name: "Ala", lastname:"Ma kota", age: 12}
const clientType = { type: "gold"}
const client={...user,...clientType}

for( let property in client )
{
 console.log(client[property])
}

const girls=["Ania","Basia","Joanna"]

console.log(girls[1]);

const girls=["Ania","Basia","Joanna"]

console.log(girls.length);

const girls=["Ania","Basia","Joanna"]

console.log(girls[0]);

const girls=["Ania","Basia","Joanna"]

console.log(girls[girls.length-1]);

const girls=["Ania","Basia","Joanna"]
const boys=["Paweł","Robert","Rafał"]
const people=[...girls,...boys]

const fewPeople=[...people.slice(3,4),...people.slice(5,6)]

console.log(fewPeople);

const girls={"Ania":1,"Basia":2,"Joanna":3}
const boys=["Paweł","Robert","Rafał"]
const people=[...Object.keys(girls),...boys]

console.log(people);

const user={"name":"Jacek","Forname":"Łoziński"}
user["age"]=45;
const hobby=["Sport","Muzyka","oraz Gry"];
user.hobby=hobby;
hobby.shift();
console.log(user);