一个字符串反转函数可实现字符串倒序

<script type="text/javascript">
var str="abcdeg";
function demo(str){
var str2="";
for(var i=0;i<str.length;i++){
str2+=str.charAt(str.length-i-1);
}

document.write(str+"<br />"+str2)
}
demo(str);
</script>

<input type="textfield" id="input"/>
<div id="result"></div>
<input type="button" value="reverse" onclick="reverse()"/> 
<script language="javascript">
function reverse()
{
var str=document.getElementById("input").value;
var a=str.split('');
var result=new Array();
while(a.length)
{
result.push(a.pop());
}
document.getElementById("result").innerHTML=result.join('');
}

</script>

var arr = new Array(3)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas" 

document.write(arr.join("."))

<script type="text/javascript">

var str="How are you doing today"

document.write(str.split(" ") + "<br />")

document.write(str.split("") + "<br />")

document.write(str.split(" ",3))

</script>

<script type="text/javascript">

var arr = new Array(3)

arr[0] = "George"

arr[1] = "John"arr[2] = "Thomas"

document.write(arr + "<br />")

document.write(arr.reverse()) 

</script>

<script type="text/javascript">
var str="Hello world!"
document.write(str.charAt(1)) 
</script>