第一次更改颜色后，轮廓颜色闪烁的JavaScript setInterval不起作用

Question

I'm trying to change the outline color of an H1 element every 2 seconds. So I used this JavaScript code... But it only changes from yellow to orange once and stays at Orange the entire time. What can I do to make it Flicker between the two colors? Please respond in JS terms and not JQuery Library

Here is my JavaScript Code, I'm new to JS :

var myVar = setInterval(function(){ colorFlicker() }, 2000);

function colorFlicker(){
    var y = document.getElementById("mainH1");
    y.style.outlineColor = y.style.outlineColor == "#ff944d" ? "#d9ff66": "#ff944d";
  }

Answer 1

Don't check for colors in javascript, the returned color depends on the browser, and is often in the format rgb(200,33,33) or rgba(244,22,244,1) or even hex in older browsers, use a flag instead

 var myVar = setInterval(colorFlicker, 500); var flag = true; function colorFlicker() { var y = document.getElementById("mainH1"); y.style.outlineColor = flag ? "#d9ff66" : "#ff944d"; flag = !flag; } 

 #mainH1 {outline: 2px solid #ff944d;} 

 <h1 id="mainH1">TEST</h1> 

Answer 2

Use rgb() for the default color then adapt your condition :

 var myVar = setInterval(colorFlicker, 1000); function colorFlicker() { var y = document.getElementById("mainH1"); y.style.outlineColor = y.style.outlineColor == "rgb(255, 148, 77)"?"#d9ff66":"rgb(255, 148, 77)"; } 

 h1 { outline-style: dotted; outline-color: rgb(255, 148, 77); } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <h1 id='mainH1'>mainH1</h1> 

Answer 3

Style changes should be handled with CSS. You can then use JavaScript to safely toggle a class that would attach the CSS style to your elements:

/* css */
#mainH1 { outline: /* some color */ }
#mainH1.alternateColor { outline: /* some other color */ }

// JS
var y = document.getElementById("mainH1");
function colorFlicker(){
  y.classList.toggle('alternateColor');
}