JavaScript学习历程03

时间:2022-04-07 14:52:09

一闪一闪亮晶晶

<script type="text/javascript">
var nn = Number(prompt('请输入一个1-9的正整数!'));
var n =nn;
var num=n;
var star="*";
// document.write(num01);
for (var i = 0; i < n; i++) {

for (var j = 0; j < num; j++) {
document.write(star)

}
--num;
document.write(n);
document.write(
"<br />");
}
n
=nn;
for (var i = 1; i < n; i++) {

for (var j = 0; j < i+1; j++) {
document.write(star)

}
document.write(n);
document.write(
"<br />");
}

</script>

 

window对 图片自动切换 要求:使用延时器和定时器来制作。

<script type="text/javascript">
var i=0;
window.onload
=function()
{
window.setInterval(Getimg,
100);
}
function Getimg()
{
++i
var imgObj=document.getElementById("imgId");
imgObj.src
="images/dd_scroll_"+i+".jpg";
if (i==6)
{
i
=0;
}
}
</script>
</head>
<body>
<img id="imgId" src="" />
</body>

 

点出满天小星星

<script type="text/javascript">
function start2(e)
{
var x=e.clientX;
// document.write(x);
var y=e.clientY;
// document.write(y);

// 创建节点
var imgObj=document.createElement("img");
// 挂载节点
document.body.appendChild(imgObj);
     
imgObj.src
="1.png";
imgObj.width
=getRandom(20,50);
imgObj.style.position
= "absolute";
imgObj.style.left
= x-imgObj.width/2 + "px";
imgObj.style.top = y-imgObj.width/2 + "px";


// imgObj.style.left=
}
function getRandom(min,max)
{
var random=Math.random()*(max-min)+min;
return random;
}


</script>