Quick Reference
The Array includes() method returns true if an array contains a specified value, and returns false if the value is not found.
<!-- html element to place output -->
<p id='my_cars'></p>
// array
let cars = ['Lamborghini', 'Ferrari', 'Maserati', 'Alfa Romeo'];
// look for Maserati starting from index position 2
document.getElementById('my_cars').innerHTML = 'Found: ' + cars.includes('Maserati', 2);
The way this works (see Syntax section below):
- The includes() method cycles through the array from a specified starting position (in this case 2) looking for a specified value (Maserati); if found, it will return true; if not, it will return false
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
Found: true
Syntax
array.includes(element, start)
Parameters
Parameter | Description |
---|---|
element | The value to search for (required) |
start | Start position (default is 0) |
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)
We’d like to acknowledge that we learned a great deal of our coding from W3Schools and TutorialsPoint, borrowing heavily from their teaching process and excellent code examples. We highly recommend both sites to deepen your experience, and further your coding journey. We’re just hitting the basics here at 1SMARTchicken.