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Start your free trialDavid Ryan
Courses Plus Student 14,981 PointsMake sirens?
Okay, so how would I make this into a bunch of flashing lights?
const div1 = document.getElementById('first');
const div2 = document.getElementById('second');
const div3 = document.getElementById('third');
function makeRed(element) {
element.style.backgroundColor = "red";
}
function makeWhite(element) {
element.style.backgroundColor = 'white';
}
function makeBlue(element) {
element.style.backgroundColor = "blue";
}
function addStyleToElement(element, callback) {
callback(element);
}
2 Answers
Steven Parker
231,236 PointsOne way to make things "flash" is to use CSS animation to change the opacity over time, and it requires no JavaScript. For example, the following code will make anything that has the class "blink" appear and disappear every second:
.blink {
animation: blink 1s linear infinite;
}
@keyframes blink {
50% { opacity: 1 }
51% { opacity: 0 }
100% { opacity: 0 }
}
David Ryan
Courses Plus Student 14,981 PointsOkay I see. I was figuring you could just create a function with timeInterval to switch the divs colors every second. This is from the callback functions lesson. I am a little confused on how to proceed with a function using the above code I pasted.
Thanks
Steven Parker
231,236 PointsSwitching colors is a job for JavaScript anyway. Here's a sample function that uses your code:
function switchColors(element) {
setInterval(function () {
if (element.style.backgroundColor == "red")
makeWhite(element);
else if (element.style.backgroundColor == "white")
makeBlue(element);
else
makeRed(element);
}, 1000);
}
KRIS NIKOLAISEN
54,971 PointsI added a makeFlash function to the video's workspace in this snapshot that uses setInterval
Steven Parker
231,236 PointsSteven Parker
231,236 PointsThis is just a few support routines, none of which are being called. Did you mean to post a more complete project including some HTML componen(s)? If possible, make a snapshot of your workspace and post the link to it here.