The keys function in Javascript creates an object of the type array iterator, which holds the keys of the array. The general syntax for the keys function is as follows:
array.keys()
The keys function takes no mandatory input as an argument.
The keys function returns an array iterator object, which can be used to iterate the keys of an array.
The example below will help you understand the keys function in more depth. First, we include the working days of a week in an array and call the keys function on the array to create an array iterator object. Once we have an array iterator, we can use it to iterate over the array’s keys by using a for loop and printing each key to the console. In this example, we print each index and its value.
const array_days = ["Monday", "Tuesday", "Wednesday", "Thursday","Friday"];const iterator = array_days.keys();for (let x of iterator) {console.log(`iterator value ${x} corresponds to ${array_days[x]}`);}
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