lnked

constructor() {
        this.state = {
            counter: 0,
            items: [1, 2]
        };
    }

    increase(this) {
        this.state.counter++;
    }

    addItem() {
        this.state.items = this.state.items.push(this.state.items.length+1);
    }

this.state.items = this.state.items.push(this.state.items.length+1);

this.setState({items: ...this.state.items, this.state.items.length+1});

useEffect(() => {

        setData(props.items.map((elem) => {   // setData
            return elem.weight
        }))

      } , [data, props.items] })    // data?

let data = {};

await fetch(url).then((res) => res.json()).then(json => {
    data = { temperature: json.main.temp }
})
return data;

this.setState(() => {
    return { weather: this.askForWeather.getNeededData() }
});

this.askForWeather.getNeededData().then(weather => {
  this.setState(() => ({ weather }));
});

<Main temperature={this.state.weather.temperature}/>

{this.state.weather && <Main temperature={this.state.weather.main.temp} />}

const [page, setPage] = useState(1);
const itemsPerPage = 8;
...
{orgs.slice((page - 1) * itemsPerPage, page * itemsPerPage).map(...)}
...
<button onClick={() => setPage(page + 1)}>Next</button>
<button onClick={() => setPage(page - 1)}>Previous</button>