- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4510
Just short note to my self. If getElementById doesn't work, most probably I forgot window.onload, because if page is not loaded yet, and javascript is executed, then my element with ID will not exist. So, html part looks like:
<!DOCTYPE html> <html> <head> <script type="text/javascript" src="/arrayAssignment.js"></script> </head> <body> Variable <strong>A</strong>: <span id='varA'></span> <br/> <strong>var b = a</strong>: <span id='b=a'></span> <br/> b.splice(3); <br/> Variable <strong>A</strong>: <span id='bSplice'></span> <br/> </body> </html>
and javascript part should lok something like:
window.onload = function() {
var a = [];
var b = [];
a = [1, 2, 3, 4]
b = a;
document.getElementById("varA").innerHTML = a;
document.getElementById("b=a").innerHTML = b;
b.splice(3);
document.getElementById("bSplice").innerHTML = a;
};
This is just short note to myself since I always forget onLoad part :)
- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4266
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:
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:
b = [].concat(a);
Taken from here.
- Details
- Written by: Stanko Milosev
- Category: JavaScript
- Hits: 4464
<!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: 4081
var tableProperties = {
aoColumns: []
};
for (var i = 0; i < 9; ++i) {
var obj = {
_origColumnPosition: i
};
tableProperties.aoColumns.push(obj);
}