if...else
. :
| if () { } else { , } |
?
:
| if () { } // |
switch
switch . -. ( ):
| switch () { case 1: [break] case 2: [break] [default: ] } |
, , .
, . 2 : true false ( 1 0). .
. .
Web-. Java Script, .
while
while :
while () {
// ,
}
.
var i = 3;
while (i) { // i, 0, false
alert(i);
i--;
}
dowhile
, do..while:
do {
//
} while ();
, , , , .
var i = 0;
do {
alert(i);
i++;
} while (i < 3);
for
for. :
for (; ; ) {
//... ...
}
, alert(i) i 0 2 ( 3):
var i;
for (i = 0; i < 3; i++) {
alert(i);
}
21) Web-. Java Script
, - -. "on+ ", : onlick.
, JavaScript - , . , , , mouseover ( ) mousemove ( ), .
:
1) HTML-
inline-, on.
, click input, onlick :
<input id="b1" value=" " onclick="alert('!');" type="button"/>
? - , .
|
|
|
. - .
. , input count_rabbits(). onClick:
<html>
<head>
<script type="text/javascript">
function count_rabbits() {
for(var i=1; i<=3; i++) {
// +
alert(" "+i+" !")
}
}
</script>
</head>
<body>
<input type="button" onclick="count_rabbits()" value=" !"/>
</body>
</html>
2)
- - on c . JavaScript.
:
1.
2. on+
click id="myElement":
document.getElementById('myElement').onclick = function() {
alert('')
}
<input id="myElement" type="button" value=" "/>
, , :
function doSomething() {
alert('')
}
document.getElementById('button').onclick = doSomething;
getElementById HTML-, - .
- .
: .
