1,JS-String对象(频繁)
<script>
var str = "hello world";
console.log(str.length);
console.log(str.charAt(4));
console.log(str.substring(6));
document.write(str+"<br/>");
document.write(str.big());
</script>
String:
和java通用方法:charAt() concat() substring() split() replace()...
和特效有关的方法(会加标签):big() blink()...
JS特有的:substr()....
2,JS-Array对象(频繁)
<script>
var arr = [11,22,33];
console.log(arr.length);
console.log(arr.join("#"));
console.log(arr.pop());
console.log(arr);
console.log(arr.push(44,55,66));
console.log(arr);
console.log(arr.reverse());
console.log(arr);
</script>
看作java中ArrayList
3,JS-案例:验证码切换
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
<script type="text/javascript">
function change(){
//进行验证码切换
var img = document.getElementById("verifyCodeImage");
img.src="http://localhost:8080/vc/verifyCode?t="+new Date().getTime();
}
</script>
</head>
<body>
<img id="verifyCodeImage" src="http://localhost:8080/vc/verifyCode" onclick="change()" style="cursor: pointer;"/>
<a href="javascript:void(0)" onclick="change()">看不清,换一张</a>
</body>
</html>
小结:
想要通过src切换图片,改变src路径,如果src路径不能改变,但还要进行再次访问。通过改变?的参数列表,来让地址栏和之前产生区别