Use js to write interlaced color changes and random colors

Use js to write interlaced color changes and random colors

Don't say much, let's first upload the rendering

HTML code:

css:

#threebox {
            width: 600px;
            border: 1px solid greenyellow;
            margin: 0 auto;
        }

html:

<p>3、隔行变色</p>
    <div id="threebox">
        <input type="button" value="变" onclick="bian()">
        <ul id="threeOli">
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
        </ul>
    </div>

javascript code:

let threeOli = document.getElementById("threeOli").children;
    var threecolor;
    function bian() {
        for (let j = 0; j < 6; j++){ //循环6次生成6位颜色值
            if(j%6==0){     //如果颜色值是6位让其加上#号进行下面的代码
                threecolor="#";
            }
            threecolor += Math.floor(Math.random()*16).toString(16);//产生随机颜色
        }
        for (let i = 0; i < threeOli.length; i++){
            if (i % 2 == 0) {  
                threeOli[i].style.backgroundColor = threecolor;//偶数行进行颜色赋值
            }else {
                threeOli[i].style.backgroundColor = ""; 
            }
        }
    }