“So erhalten Sie den Index eines Objekts innerhalb einer Karte js” Code-Antworten

So erhalten Sie den Index eines Objekts innerhalb einer Karte js

To find an index of the current iterable inside the JavaScript map() function, 
you have to use the callback function's second parameter. 
An index used inside the JavaScript map() method is to state the
position of each item in an array, 
but it doesn't modify the original array.