我在将类组件中的函数转换为函数时遇到问题

Question

from this function, How can I convert "this.state" to use in functional.

  const handleDayClick = (day) => {
        const range = DateUtils.addDayToRange(day, this.state);
        setRange(range)
    }

Answer 1

If you used useState like this

const [range, setRange] = useState({});

then you need to use another variable name in the handle function.

const handleDayClick = (day) => {
    const newRange = DateUtils.addDayToRange(day, range);
    setRange(newRange);
}

Answer 2

this pointer doesn't work in functional component and you have to use hooks, so add this line

const [range, setRange] = React.useState({});

Then change this.state to range