JavaScript 学习笔记2.
var sMyString = "Tsinghua Universary";
alert(sMyString.charAt(4));从某个字符串仲取出其中的一段子字符串,可以采用slice()、substring()或substr()方法。
<title>slice()和substring()</title>
<script>
var sMyString = "Tsinghua Universary";
document.write(sMyString.slice(1,3)+"<br>");
document.write(sMyString.substring(1,3)+"<br>");
document.write(sMyString.slice(4)+"<br>");
</script>
搜索操作返回值都是子字符串开始的位置
<title>indexOf()和lastIndexOf()</title>
<script language= "javascript">
var sMySting = "Tsinghua Universaty";
document.write(sMyString.indexOf("i")+"<br>");
document.write(sMyString.indexOf("i", 3)+"<br>");
document.write(sMyString.indexOf("i)+"<br>");
2.3.3布尔型
<title>布尔型</title>
<script language = "javascript">
var married = ture;
alert("1."+typeof(married));
married = "ture"
alert("2."+typeof(married));
</script>
2.3.4 类型转换
toStirng()
数值转换为字符串类型,可以直接+ 将熟知为零的空字符串,或者通过toString()方法。
parseInt() 将字符串转换为数值类型。
2.3.5 数组
在JavaScript脚本仲,数组使用关键字Array来声明。
var aTeam = new Array(12);
<script language = "javascript">
var aMap = new Array("China", "USA","Britain");
aMap[20] = "Korea";
join()方法指定转换后字符串间的连接符(把数组转化成字符串)
split()方法讲字符串转换为数组;
var sFruit = "apple, pear,peach,orange";
var aFruit = sFruit.split(",");
reverse()方法可以用来是数组元素反序;
用split()方法是字符串的反序排列 牛啊!
var sMyString = "abcdefg";
alert(sMyStrig.split("").reserve().join(""));
/*split("")将每一个字符转化为一个数组元素
reserved()反序数组的每个元素
join("")最后将数组无连续符地转化成字符串
*/
sort()方法进行数组元素排序
<title>sort()方法<title>
<script language = "javascript">
var aFruit = {"pear", "apple", "peach","orange"};
aFruit.sort();
altert(aFruit.toString());
</script>
//public String toString()
返回此对象的字符串标识形式。
push()压栈和pop()出栈。
<title>栈</title>
<script language = "javacript">
var stact = new Array();
stack.push("red");
stack.push("green");
stack.push("blue");
document.write(stack.toString() + "<br>");
var vItem = stack.pop();
document.write(vItem+"<br>");
document.write(stack.toString);
</script>