return an array with element with tag name, with order they appear in the page
document.getElementByTagName("div")
2008年9月14日 星期日
regular expression in javascript
syntax:
/ expression /
. : match any character other than newline
\s: match a whitespace character
\d: match number
\w: match alphanumeric character
^: beginning of the string
$: end of the string
\: escape character
quantifiers:
* : o or more times
+: 1 or more times
?: o or 1 time
{ n} : n times
{min, max}:
[abc]: a or b or c
regular expression is a RegExp object
how to use:
ex:
var key= /\d/;
if( key.test( "32") )
{
alert("matched");
}
2008年8月27日 星期三
control logic ( if & switch)
switch , case, break , default:
the same as C syntax
if , else :
the same as C syntax
the same as C syntax
if , else :
the same as C syntax
2008年8月14日 星期四
document object
document.body.clientHeigth:
client window height
document.body.clientWidth:
client window width
document.getElementById("elementName")
document.cookie:
set cookie:
ex:
document.cookie="name1=peter;expires=1/1/2000;";
how to clear cookie:
set it value to "" & expiration data to -1
2008年6月12日 星期四
getElementById
getElementById
get html element
ex:
html element:
input type="text", id="test", name="abc"
javascript:
document.getElementById("test").value
access data from value
math methods
NaN:
not a number
parseInt():
convert test to integer
ex:
parseInt("1");
parseFloat()
isNaN():
ex:
var a=3;
isNaN(a);
toFixed():
ex:
a=3.333;
a.toFixed(2);
---> a=3.33
variable , constant, function
variable:
ex:
var test=300;
constant:
ex:
const TEST= 300;
function:
ex:
function test() {
}
call two methods:
ex:
<body onload ="test(); test2();">
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