JavaScript Reference
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Quick Reference

The Array entries() method returns an array iterator object that shows the key and value pairs currently existing within the array.

<!-- html element to place output -->
<p id="my_cars"></p>
// array
let cars = ['Lamborghini', 'Ferrari', 'Maserati', 'Alfa Romeo', 'Astin Martin', 'Porsche'];

// get key/value pairs
const c = cars.entries();

// cycle through the entries and output the key/value pairs
for (let x of c) {
    document.getElementById('my_cars').innerHTML += x + '<br>';
}

Note

Arrays count starting from zero NOT one. So item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on.

Output

0,Lamborghini
1,Ferrari
2,Maserati
3,Alfa Romeo
4,Astin Martin
5,Porsche

Syntax

array.entries()

JavaScript Notes:

  • When using JavaScript, single or double quotation marks are acceptable and work identically to one another; choose whichever you prefer, and stay consistent
  • JavaScript is a case-sensitive language; firstName is NOT the same as firstname
  • Arrays count starting from zero NOT one; so item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on
  • JavaScript variables must begin with a letter, $, or _
  • JavaScript variables are case sensitive (x is not the same as X)
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