add index to foreach javascript code example

Example 1: javascript foreach index

users.forEach((user, index)=>{
	console.log(index); // Prints the index at which the loop is currently at
});

Example 2: javascript enumerate with index

const iterable = [...];
for (const [index, elem] in iterable.entries()) {
  f(index, elem);
}

// or
iterable.forEach((elem, index) => {
  f(index, elem);
});