Array of integers using the Array.from() method

This code is using the Array.from() method to generate an array of numbers from 1 to 5.

Array.from({ length: 5 }, (_, x) => x + 1)
// > Array [1, 2, 3, 4, 5]

Array.from({length: 10}, (_, x) => x + x );
// > Array [0, 2, 4, 6, 8, 10, 12, 14, 16, 18]

• Array.from() is a built-in JavaScript method that creates a new array from an iterable or array-like object. It takes an iterable object as its first argument and an optional mapping function as its second argument.
• { length: 5 } is an object literal with a length property set to 5. In this context, it is acting as an iterable object. This object represents a sequence of 5 items with undefined values.
• (_, x) => x + 1 is a mapping function. The first parameter _ is a placeholder for the current element, and x represents the current index. The function increments the index x by 1, effectively generating an array of numbers starting from 1.

When Array.from() is called with the iterable { length: 5 } and the mapping function, it creates an array of numbers from 1 to 5.