如何使用 typescript 修复字符串类型的错误参数或未定义的参数不可分配给字符串类型的参数并做出反应？

Question

i am getting error argument of type string or undefined is not assignable to parameter of type string using typescript and react

below is my code,

    function List({items}: Props) { 
        const [activeindex, setActiveindex] = React.useState<string>();
        return (
            items.map((item: any) => {
                <AddButton setActiveIndex={setActiveIndex} itemId={item.id}/>
            }
        );
    }

    
    interface AddButtonProps {
        setActiveIndex: any;
        itemId?: string;
    }
    function AddButton ({setActiveIndex, itemId}: AddButtonProps){
        const {toggleDrawing} = useDrawing();
        const handleClick = (itemId) => {
            setActiveIndex(itemId);
            toggleDrawing(itemId); //error here
        }
        return (
            <Button onClick={handleClick}/>
        );
    );


    function useDrawing () {
        const [editableItemId, setEditableItemId] = React.useState<string>();
        const toggleDrawing = React.useCallback(async (itemId: string) => {
            if (isDrawing && editableItemId === itemId) {
                cancelDrawing();
            } else if (isDrawing) {
                cancelDrawing();
                setEditableItemId(itemId);
            } else {
                setEditableWorkAreaId(itemId);
            }
        },
            [isDrawingPolygon, editableItemId, cancelDrawing]
    );
}

I am not sure why i am getting this error. could someone help me fix this. thanks.

Answer 1

try this way;)

const toggleDrawing = React.useCallback(async (itemId: string | undefined) => {
    if (isDrawing && editableItemId === itemId) {
        cancelDrawing();
    } else if (isDrawing) {
        cancelDrawing();
        setEditableItemId(itemId);
    } else {
        setEditableWorkAreaId(itemId);
    }
   },[])

Answer 2

You interface defines itemId?: string; and a string or undefined but the function call needs a string.

Use either

if (itemId) {
  toggleDrawing(itemId);
}

or

toggleDrawing(itemId || '');

or

toggleDrawing(itemId as string);