Quick Reference
The Array forEach() method calls a function, running it for each item in an array.
<!-- html element to place output -->
<p id="my_cars"></p>// arrays
let text = ""; // empty array
let cars = ['Lamborghini', 'Ferrari', 'Maserati', 'Alfa Romeo'];
// function to run
function my_function(item, index) {
text += 'Index: ' +index + ', Car: ' + item + '<br>';
}
// call function and use forEach
cars.forEach(my_function);
// output the results of the function for each array item
document.getElementById('my_cars').innerHTML = text;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
Index: 0, Car: Lamborghini
Index: 1, Car: Ferrari
Index: 2, Car: Maserati
Index: 3, Car: Alfa RomeoSyntax
array.find(function(currentValue, index, arr),thisValue)Parameters
| Parameter | Description |
|---|---|
| function() | A function to be run for each element in the array (required) |
| currentValue | The value of the current element (required) |
| index | The index of the current element |
| arr | The array of the current element |
| thisValue | A value passed to the function as its "this" value (default is undefined) |
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.