- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4541
It seems that javascript considers array as a pointer, therefore, simple assignment like:
a = b
will not copy values, variable a will just "point out" to variable b.
Consider following example:Â
var a = []; var b = []; a = [1, 2, 3, 4] b = a; b.splice(3);
In this case, variable a will be 1, 2, 3
Full example you can see here.
Solution is something like:Â
b = [].concat(a);
Taken from here.
- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4747
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<title></title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<script>
function errorTimeOut(strInTest) {
alert('I will wait 10 seconds, but no variables (error: Uncaught ReferenceError: strTest is not defined). ' + strInTest)
}
function errorAlert() {
var strTest = "I am here!";
setTimeout("errorTimeOut(strTest)", 10000);
}
function correctTimeOut(strInTest) {
alert('I was waiting 20 seconds, and everything is ok: ' + strInTest)
}
function correctAlert() {
var strTest = "I am here!";
setTimeout(function() {
correctTimeOut(strTest)
}, 20000);
}
setTimeout(alert('I am fired immediately'), 10000);
errorAlert();
correctAlert();
</script>
</head>
<body>
</body>
</html>
As you can see from previous code, setTimeout(alert('I am fired immediately'), 10000); will not work.
setTimeout("alert('I will wait')", 10000); - this will work, alert under quotes, but you can not pass varibles.
And the code:
function correctAlert() {
var strTest = "I am here!";
setTimeout(function() {
correctTimeOut(strTest)
}, 20000);
}
Will work properly.
- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4305
var tableProperties = {
aoColumns: []
};
for (var i = 0; i < 9; ++i) {
var obj = {
_origColumnPosition: i
};
tableProperties.aoColumns.push(obj);
}
- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4327
String.prototype.test = function () {
alert('prototype');
}
var a = "";
a.test();