javascript 之 RegExp Function String
ECMAScript通过RegExp类型来支持正则表达式
<script type="text/javascript">
var pattern1 = /\[bc\]at/i;
alert(pattern1.global); //false
alert(pattern1.ignoreCase); //true
alert(pattern1.multiline); //false
alert(pattern1.lastIndex); //0
alert(pattern1.source); //"\[bc\]at"
var pattern2 = new RegExp("\\[bc\\]at", "i");
alert(pattern2.global); //false
alert(pattern2.ignoreCase); //true
alert(pattern2.multiline); //false
alert(pattern2.lastIndex); //0
alert(pattern2.source); //"\[bc\]at"
</script>
Function类型
1.没有函数重载
2.解析器会先读函数声明,使其在执行任何代码之前可用,函数表达式必须要等到解析器执行到所在行才可以
<script type="text/javascript">
alert(sum(10,10)); //20
function sum(num1, num2){
return num1 + num2;
}
</script>
3.函数也可以作为值返回
<script type="text/javascript">
function callSomeFunction(someFunction, someArgument){
return someFunction(someArgument);
}
function add10(num){
return num + 10;
}
var result1 = callSomeFunction(add10, 10);
alert(result1); //20
function getGreeting(name){
return "Hello, " + name;
}
var result2 = callSomeFunction(getGreeting, "Nicholas");
alert(result2); //Hello, Nicholas
</script>
String 类型
<script type="text/javascript">
var stringObject = new String("hello world");
var stringValue = "hello world";
alert(typeof stringObject); //"object"
alert(typeof stringValue); //"string"
alert(stringObject instanceof String); //true
alert(stringValue instanceof String); //false
</script>
URI编码方法
<script type="text/javascript">
var uri = "http%3A%2F%2Fwww.wrox.com%2Fillegal%20value.htm%23start";
//http%3A%2F%2Fwww.wrox.com%2Fillegal value.htm%23start
alert(decodeURI(uri));
//http://www.wrox.com/illegal value.htm#start
alert(decodeURIComponent(uri));
</script>