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JavaScript - Try Catch Or Another Way...
Ok I have a script that uses some global arrays and a function that looks like this:
function functName(p) The other params are optional so they are accessed using: functName.arguments[1] etc. My problem is an error that I can't seem to catch even though it's an easy one. array = (functName.arguments[1] != undefined && evel('window.' +functName.arguments[1]) != undefined) ? do this: or this; The second param is an arrayName. It can be sent to the function as a string or a reference ( string: 'arrayName' , ref: arrayName) both operate correctly unless the array doesn't exist. Entered as a string, if the array doesn't exist it defaults to another array as required. However, if posted as a reference and it doesn't exist it throws an error: 'arrayName' is undefined Should I just use a 'try catch' method or it just something simple I missed? Similar TutorialsHi I'm an AS3 dev learning Javascript. I'm currently writing a simple script that loads an image as seen below. I deliberately misspell the file name to test the fail. Code: var fileName = "anImageThatDoesntExist.jpg";
var image = new Image();
image.onload = imageLoaded;
try {
image.src = "images/" + fileName;
} catch( error ) {
console.log('load error', error.message );
} finally {
console.log('unable to catch error!')
}
function imageLoaded( event ) {
console.log('image loaded');
}
When I run this script I was expecting the 'catch' to pick up the error and tell me that the file doesn't exist. The 'catch' statement is ignored and 'finally' is executed. I would be very grateful if someone could let me know if I'm writing the try/catch incorrectly or whether it doesn't work in this way when loading an image. Many thanks in advance.... What happens in Javascript when you do not catch a thrown exception? Does the script get terminated prematurely? Hi all, I have a question about following code. It is tested as working well but the problem is that I need to catch values of array registos from javascript function getData(dataSource, sql_str) in PHP and not only update values of each form element. Can you help me, plz? Code: <script language = "javascript">
function getData(dataSource, sql_str){
if (window.XMLHttpRequest){
xmlhttp=new XMLHttpRequest();
}
else{
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function(){
if (xmlhttp.readyState==4 && xmlhttp.status==200){
var registos = eval('('+xmlhttp.responseText+')');
document.getElementById("id_1").value=registos["cliente"];
document.getElementById("id_2").value=registos["designacao"];
}
}
xmlhttp.open("GET", dataSource+"&sql_str="+sql_str,true);
xmlhttp.send();
}
</script>
<?php
$sql_str="SELECT cliente, designacao WHERE cliente = '$cliente'";
$record=$db->sql_query($sql_str);
list($registos[cliente], $registos[designacao]) = $db->sql_fetchrow($record);
echo "<form id=\"form\">";
echo "<input type=\"text\" id=\"id_1\" name=\"registos[cliente]\" value=\"".$registos[cliente])."\">";
echo "<br>";
echo "<input type=\"text\" id=\"id_2\" name=\"registos[designacao]\" value=\"".$registos[designacao]."\">";
echo "<br>";
echo "<input type=\"button\" value=\"CONFIRMAR\" onclick=\"getData('mysql_query.php', '".base64_encode(serialize($sql_str))."')\">";
echo "</form>";
I've got a function that returns the value of a radio button group. However the application allows to "hide" some groups on others responses and that effectively make the radio groups not exist. This causes issues with calculations using the total value of the groups combined. I need a way to return a value of '0.00' IF the function does not find the group/returns an error.This is what I currently got to but doesnt work. The function does not work at all. Code: function funcRadioCalc(RadioName)
{
var chkList1= document.getElementById (RadioName);
var arrayOfCheckBoxes= chkList1.getElementsByTagName("input");
var bob;
try {
for( var i=0;i<arrayOfCheckBoxes.length;i++){
if (arrayOfCheckBoxes[i].checked) {
bob= arrayOfCheckBoxes[i].value;
if (bob!=undefined||bob!=""){
throw "yep";
}else{
throw "nope";
}
}
}
catch (er){
if(er=="nope")
{
return "0.00";
}
if(er=="yep")
{
return bob;
}
}
}
If you try some codes and then catch exception, it should catch the exception when there is. However, if there is a setInterval method in the try clause, then the exception cannot be caught... why??? the following works ( a usual method is invoked in the try clause): Code: <script language="javascript" type="text/javascript">
function invoke()
{ var i=0;
return i.x.y;
}
try
{
alert(invoke());
}
catch(ex){ alert(ex); } //Any Exception will be caught.
</script>
if the highlighted line is changed as below (using setInterval method), then it fails... Code: <script language="javascript" type="text/javascript">
function invoke()
{ var i=0;
return i.x.y;
}
try
{
setInterval(alert('invoke())',1000);
}
catch(ex){ alert(ex); } //The Exception will NOT be caught.
</script>
any idea? thx in advance I would like to create a link from one page to another. Easy - I know. But I would like that link to to take me to a certain part of the other page, specifically towards the bottom of the page. Is that possible to do? And if so, what are the different ways I can specify where in the page to go? (i.e. what are the parameters that I can play with) Thanks! |
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