Quick Reference
The Window setInterval() method calls a function at specified intervals (in milliseconds).
<!-- html element to place output -->
<p id="my_output"></p>The following sets a timer that resets every one second (1000ms). The timer is then placed on the page and would increment the timer with each reset, basically counting forward like a clock.
// timer
let my_interval = setInterval(my_timer, 1000);
// place time on the page
function my_timer() {
let date = new Date();
document.getElementById('my_output').innerHTML = date.toLocaleTimeString();
}Output
2:27:39 PMSyntax
setInterval(function, milliseconds, param1, param2, ..., etc.)Parameters
| Parameter | Description |
|---|---|
| function | The function to be executed (required) |
| milliseconds | The execution interval; if the value is less than 10, 10 will be used (required) |
| param1, param2, ..., etc. | Additional parameters, if any, to pass to the function |
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.