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JavaScript - Loop And Closure Issue
Hi, i'm looking to send a loop variable (i) to a function inside the loop, but I can't seem to get it to use the value I want, it keeps making it a reference of i and therefore the function is always called using the last value of i rather than the one it was set with.
So if i have 5 Tabs then Tab 1, when clicked, should call DefaultTabClick(0) and so on rather than always using 4 for any of the tabs. Code: for (var i = 0; i < AccountSettings.Tabs.length; i++) {
$tabs.append(CreateTabLink(AccountSettings.Tabs[i].Title, DefaultTabClick(i)));});
}
function DefaultTabClick(i) {
var i = i || AccountSettings.Tabs.length - 1;
return function () {
if (currentTab === i) {RenameTab(this);}
else {
SaveTabSettings(currentTab); //Save Current
ClearDashboard(); //Clear Current
LoadDashboardWithLayout(i); //Load Selected
}
}
}
Similar TutorialsHello... Thanks for reading... I am getting an undefined error when i try to get a value from this array in the interior loop... Code: // This is the array I am trying to access AuditTable [0] = ["Visio Modifed date","Word Modified Date","User Status","User Comment","Last Audit","Audit Status","Audit Comment"] AuditTable [1] = ["11/23/2009 8:52:18 AM","missing","OK","user comment number 1","1/1/2009","ok","audit comment number 1"] AuditTable [2] = ["11/24/2009 12:21:19 AM","missing","Out of Date","Changes from 2008 not implemented","1/2/2009","Out of Date","needs update"] AuditTable [3] = ["11/22/2009 9:24:42 PM","missing","Incomplete","Document doesnt cover all possibilities","1/3/2009","Inadequate","needs update"] I have hard coded values and had success such as: Code: data = AuditTable[1][0] But when I put the vars associated with the loop in I get an undefined error - AuditTable[i] is undefined: Code: // produces error data = AuditTable[i][j] //Works but retrieves wrong data data = AuditTable[j][i] //Works but retrieves wrong data data = AuditTable[1][i] //Works but retrieves wrong data data = AuditTable[j][2] I must be trying to access the array incorrectly or something... I have defined all the vars, and tried many combinations, alerted the values of both vars so I can prove it is not a scope issue... Am I missing something obvious? Thanks much... Code: var reportArray=new Array();
var reportData, title, subTitle, data;
for(i in parmarray)// loop thru AuditTable array and get values
{
title = '<div style="font-family:verdana; font-size:14px; font-weight:bold; margin:25px 0px 5px 30px">';
title += namearray[i][0];
title += '</div>';
reportArray.push(title);//Take compiled variable value and put it into array
for(j=0; j < AuditTable[0].length; j++)// loop thru AuditTable array and get values
{
subTitle = AuditTable[0][j];//points to first row of AuditTable where the labels are
data = AuditTable[1][0];//points to the current row where actual data is
html = i + j +'<div style="font-family:verdana; font-size:12px; color:#696969; font-weight:bold; margin-left:30px;">';
html += subTitle;
html += '</div><div style="font-family:verdana; font-size:12px; color:#a9a9a9; margin-left:30px; margin-bottom:10px">';
html += data;
html += "</div>";
reportArray.push(html);// put results into array
}
}
is this function a closure in javascript? Code: function f1(){
var n=999;
function f2(){
alert(n); // 999
}
}
is the function f2() a closure? if not? why? what's and use of a closure.could you depict it in your own words. thank you Code: function foo(x) {
var tmp = 3;
function bar(y) {
alert(x + y + (++tmp));
}
bar(10);
}
foo(2)
is the function a closure? if not? why? thank you When using anonymous wrappers (I guess they are called like that), what does "()" part do at the end of the stack? An example: Code: (
function() {}
)
() //Here!
What does it do and how can we use it? This is pretty cool; here's an online service Google has provided to scrunch your Javascript code down as small as possible. http://closure-compiler.appspot.com/home Here's the intro page... http://code.google.com/closure/compiler/ I like it! js code is as follows: Code: uniqueNo=(function(){
var no=0;
return function(){ return no++; }
})()
document.writeln(uniqueNo()); // 1st time call
document.writeln(uniqueNo()); // 2nd time call
document.writeln(uniqueNo()); // 3rd time call
the result is 1 2 3 why after the 2nd call, the declaration 'var no=0' is useless -- seems 'no' is updated and stored each time it is called? many thanks Hi all, I have a problem where I'm trying to load data into multiple divs. They are payslips, so p1, goes into january, p2 into febuary etc. I want to onLoad them all so when the page is loaded they are all displayed. Every time I try this, the loop automatically goes to the last iteration, 6 in this example, so the only div that is loaded is p6. Here is my code: function replace(slip, year) { // table contains either 'bank' or 'intranet' xmlHttpReq.open("POST", "do_payslips_ajax.php", true); xmlHttpReq.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded'); xmlHttpReq.onreadystatechange=function() { if(xmlHttpReq.readyState == 4) { document.getElementById("p" + slip).innerHTML = xmlHttpReq.responseText; } } xmlHttpReq.send(getquery(slip,year)); } function getquery(slip,year) { strQuery = "weekmonth=" + slip + "." + year; return strQuery; } function loadpayslips(year) { for (slip=1; slip<=6; slip++) { replace(slip, year); } } <label> <body onload = loadpayslips(11)> search</a> </label> <div id="p1"> /div> <div id="p2"> month 2</div> <div id="p3"> month 5</div> etc.. Any help would be appreciated. Thanks Hi all, I've got some simple code that I use to drag the corners of a DIV to resize it on the fly. One thing that bothers me is that there is a "global" variable just hanging outside and I would rather "encapsulate" it all into a block of code so that the variable persists, but is not visible outside of the code that uses it. So, here's the code: Code: /***
* support for mouse drag resize of mChat window
* "global" save of mouse start position
**/
var start = 0;
/***
* do-nothing function to attach unused events to
**/
function nullFunc () {
return false;
};
/***
* begin drag
**/
function drag () {
start = 0;
document.onmouseup = up;
document.onmousedown = nullFunc;
document.onmousemove = move;
return false;
};
/***
* end drag
**/
function up () {
start = 0;
document.onmouseup = nullFunc;
document.onmousedown = nullFunc;
document.onmousemove = nullFunc;
return false;
};
/***
* mouse move capture
**/
function move (e) {
var o = mouseXY(e); /* mouseXY not shown here */
if (start) {
mChatSize(o.y - start); /* mChatSize not shown here */
}
start = o.y;
return false;
};
You see the code captures the mouse Y coordinate and then subtracts "start" from it to generate a DELTA (which is what the mChatSize function needs). So, moving the mouse up generates "-1, -1, -1" maybe -2 if dragged fast and +1 +1 +1... if moved down.... you see? Now what I want to do is put all this code in a "box" so that "start" is global to the box, but invisible outside. I tried to do it and made no headway... I'm sure it's simple and I'm just missing it. Any help will be appreciated. Thanks! -- Roger Ok, I'm nearly pulling my hair out with this one. I have been looking at this code for two evenings now, and rewrote it 4 times already. It started out as jQuery code and now it's just concatenating strings together. What I'm trying to do: Build a menu/outline using unordered lists from a multidimensional array. What is happening: Inside the buildMenuHTML function, if I call buildMenuHTML, the for loop only happens once (i.e. only for 'i' having a value of '0'.) If I comment out the call to itself, it goes through the for loop all 3 times, but obviously the submenus are not created. Here is the test object: Code: test = [
{
"name" : "Menu 1",
"url" : "menu1.html",
"submenu" : [
{
"name" : "menu 1 subitem 1",
"url" : "menu1subitem1.html"
},
{
"name" : "menu 1 subitem 2",
"url" : "menu1subitem2.html"
} ]
},
{
"name" : "Menu 2",
"url" : "menu2.html",
"submenu" : [
{
"name" : "menu 2subitem 1",
"url" : "menu2subitem1.html"
},
{
"name" : "menu 2subitem 1",
"url" : "menu2subitem1.html"
} ]
},
{
"name" : "Menu 3",
"url" : "menu3.html",
"submenu" : [
{
"name" : "menu 3 subitem 1",
"url" : "menu3subitem1.html"
},
{
"name" : "menu 3 subitem 1",
"url" : "menu3subitem1.html"
} ]
}
];
Here is the recursive function: Code: function buildMenuHTML(menuData,level) {
var ul;
if (level == 1) {
ul = "<ul id='menu'>";
} else {
ul = "<ul class='level" + level + "'>";
}
for (i = 0; i < menuData.length; i++) {
menuItemData = menuData[i];
ul += "<li>";
ul += "<a href='" + menuItemData.url + "'>" + menuItemData.name + "</a>";
if (typeof menuItemData.submenu != 'undefined') {
ul += buildMenuHTML(menuItemData.submenu,level + 1);
}
ul += "</li>";
}
ul += "</ul>";
return ul;
}
Here is how the function is called initially: Code: buildMenuHTML(test,1); This is it's return value (with indentation added for readability): Code: <ul id='menu'>
<li><a href='menu1.html'>Menu 1</a>
<ul class='level2'>
<li><a href='menu1subitem1.html'>menu 1 subitem 1</a></li>
<li><a href='menu1subitem2.html'>menu 1 subitem 2</a></li>
</ul>
</li>
</ul>
'Menu 2' and 'Menu 3' don't show up! I'm sure it's something small that I'm overlooking, but any help would be appreciated. Hi all I'm well aware that I can't post assignments here and expect an answer, however, I have been staring at this code for so long. I feel I am close to the solution (to get the correct output to the browser) but I just cannot get it to count how many moves it takes. I don't want an answer, but a nudge in the right direction would be very grateful. As you can see from the code and the output, it will attempt to write to the browser how many moves, but only '0'. Code: function rollDie()
{
return Math.floor(Math.random() * 6) + 1;
}
/*
*searches for a number in a number array.
*
*function takes two arguments
* the number to search for
* the number array to search
*function returns the array index at which the number was found, or -1 if not found.
*/
function findIndexOf(number, numberArray)
{
var indexWhereFound = -1;
for (var position = 0; position < numberArray.length; position = position + 1)
{
if (numberArray[position] == number)
{
indexWhereFound = position;
}
}
return indexWhereFound;
}
//ARRAYS that represent the board -- you do not need to change these
//array of special squares
var specialSquaresArray = [1,7,25,32,39,46,65,68,71,77];
//array of corresponding squares the player ascends or descends to
var connectedSquaresArray = [20,9,29,13,51,41,79,73,35,58];
//VARIABLES used -- you do not need to change these
//the square the player is currently on
var playersPosition;
//play is initially at START
playersPosition = 0;
//what they score when they roll the die
var playersScore;
//the index of the player's position in the special squares array or -1
var indexOfNumber;
//MAIN PROGRAM
//TODO add code here for parts (iii), (iv)(b), (v), and (vi)
// start of question(iii)
playersScore = rollDie();
document.write(' Sco ' + playersScore);
playersPosition = playersScore + playersPosition;
document.write(', Squa ' + playersPosition);
indexOfNumber = findIndexOf(playersPosition, specialSquaresArray);
if (indexOfNumber != -1)
{
document.write(', Ladder to Squa ' + connectedSquaresArray[indexOfNumber]);
playersPosition = connectedSquaresArray[indexOfNumber];
indexOfNumber = -1;
}
document.write('<BR>')
// end of question(iii)
// start of question(iv)(b)
while(playersPosition<=80)
{
playersScore = rollDie()
document.write(' Sco ' + playersScore)
playersPosition = playersPosition + playersScore
document.write(', Squa ' + playersPosition)
indexOfNumber = findIndexOf(playersPosition, specialSquaresArray)
if(indexOfNumber != -1)
{
document.write(', Ladder to Squa ' + connectedSquaresArray[indexOfNumber]);
playersPosition = connectedSquaresArray[indexOfNumber];
}
document.write('<BR>');
}
var countMoves = 0;
while(countMoves <= 0)
{
document.write('You took ' + countMoves + ' moves to get out');
countMoves = countMoves + 1
}
/*for (var countMoves = 0; countMoves < playersPosition; countMoves = countMoves + 1)
{
countMoves = countMoves + playersPosition;
document.write('You took ' + countMoves + ' moves to get out');
}*/
// end of question(iv)(b)
// start of question (v)
/*if (playersPosition >=80)
{
document.write('The player is out');
}*/
// end of question (v)
</SCRIPT>
</HEAD>
<BODY>
</BODY>
</HTML>
Many thanks. Hi, I am doing some studying and we was to create a small loop using either the for loop, while loop or do while loop. I chose to do the for loop because it was easier to understand, but I want to know how to do the same using the while loop. Here is the for loop I have, but I cant figure out how to change to while loop. Code: for (var i = 0; i < 5; ++i)
{
for (var j = i; j < 5; ++j)
{
document.write(j + "");
}
document.write("<br />");
}
output is equal to: 01234 1234 234 34 4 How do you make the same using a while loop? it wont loop, as long as you enter something in the name field it will submit. also how do i stop from submitting if all fields are not filled out? any help will be appreciated) ====== function checkForm(form) { var len = form.elements.length; var h=0; for (h=0; h<=len; h++){ if ((form.elements[h].value==null) || (form.elements[h].value=="")){ alert("Please enter "+document.myForm.elements[h].name); document.myForm.elements[h].focus(); return false; } return true; } } ===body-== <FORM NAME="myForm" METHOD="post" ACTION="http://ss1.prosofttraining.com/cgi-bin/process.pl"> Name:<BR> <INPUT TYPE="text" size="30" NAME="name"><br> Email address:<BR> <INPUT TYPE="text" size="30" NAME="email address" onBlur="emailTest(this);"><br> Phone number:<BR> <INPUT TYPE="text" size="30" NAME="phone number"><br> Fax number:<BR> <INPUT TYPE="text" size="30" NAME="fax number"><p> <INPUT TYPE="submit" VALUE="Submit Data" onClick="return checkForm(this.form);"> <INPUT TYPE="reset" VALUE="Reset Form"> </FORM> Hello, I recently purchased a JavaScript book, and I am confused by one of it's examples. I was wondering if anybody could answer my question. Here is the example: for (loopCounter = 1; loopCounter<= 3; loopCounter++) { //execute this code } Now, what I need help with is the variable part. The book goes on to say: ""To keep track of how many times you have looped through the code, you need a variable to keep count" My question is: Why does the variable have the value of one and not another number? I'm very very new to JS, I understand that the loopCounter has to be les than or equal to 3 for the code to execute, and also that it is incremented by one each loop, but the book is not clear on why the value of the variable has been set to 1. If anybody could answer this question I would be very grateful, I hate moving onto the next stage of a book if I do not completely understand the previous topics. Thank you in advance Hi All, im trying to to use a for loop to loop through a drop down list of users and if there is a match between the user logged in and the drop down list i want to enable two fields, if the user logged in isnt in the drop down list i want to disable the two fields, but im having trouble looping through, iv tried ".value" with no avail.. heres my Script Code: var RequestingUser = document.getElementById('JoinersLeaversContent_cmbRequestingUser').text;
var Authorisers = document.getElementById('JoinersLeaversContent_ddlAuthoriseId');
for (var i = 0; i < Authorisers.length; i++)
{
if (RequestingUser.text == Authorisers.value) {
document.getElementById('JoinersLeaversContent_txtAuthoriserSig').disabled = false;
document.getElementById('JoinersLeaversContent_txtDateSignedOff').disabled = false;
}
else
{
document.getElementById('JoinersLeaversContent_txtAuthoriserSig').disabled = true;
document.getElementById('JoinersLeaversContent_txtDateSignedOff').disabled = true;
}
}
So just to be clear, if the user logged in appears in the drop down box i want to enable the two fields, if they dont appear i want to disable the two fields Please help. Thank you Hey guys i've just been following a few tutorials and learnt how to do a for loop and a while loop, what is the major difference between the two? they seem quite similar? I know while loops are laid out a hell of a lot easier in my opinion!
I have a form that shows or hides divs based on what is chosen in a dropdown. There are 4 divs but only one is shown and the other 3 hidden based on dropdown selection. Inside each div are checkboxes with items for sale. I want to reset the checkboxes to unchecked and the line total values to 0 if the div is hidden. I've got the checkboxes to reset but I can't figure out how to set the line total values to 0 (There are 14 total so I'm trying to loop thru all of them and reset them.) This is what I have in the loop Code: for (var i = 0; i < form.elements.length; i++ ) {
if (form.elements[i].type == 'checkbox') {
form.elements[i].checked = false;
}
}
// set line_totals to 0
for (var j = 0; j< form.elements.length; j++ ) {
if (form.elements [j].name.substring(0,10) == 'line_total') {
form.elements[j].value = '';
}
}
Hello all. I am faitly new at programming and have run into a little problem. I want to create a script that creates 2 random numbers, stored in 2 different variables and then compare them to eachother. there is two possible outcome of that comparison, either they are different or they are alike. If they are different i want to randomize a new set or numbers and make a other comparement, also to keep track on how many times i have created numbers. If they are alike i want to display the numbers and how many tries it took to get a matching pair. atm it looks like this <html> <body> <script> var x=(Math.floor(Math.random()*6)+1); var y=(Math.floor(Math.random()*6)+1); //creates two random int between 1 and 6 var throws = 1; //keep tabs on how many times we have thrown the dices if(x!=y) { x=(Math.floor(Math.random()*6)+1); y=(Math.floor(Math.random()*6)+1); throws=throws+1 }else{ document.write("you have rolled a pair. Dice 1 is: " +x +" and Dice 2 is: " +y +" and it took " +throws +" tries to get a pair."); } </script> </body> </html> How to get that into a loop? a really confused newbie scripter For those who read my other thread I finally scratched together the code to take a value from an XML file and add it to a select box as an option. Ofcourse it only does it once so I need to loop it. It's kinda complex though, here's a function line to add one option: addOption(document.people_form.People,name2,office2) And here's the code in the head: <script type="text/javascript"> //load xml file if (window.ActiveXObject){ var xmlDoc = new ActiveXObject("Microsoft.XMLDOM"); xmlDoc.async=false; //Enforce download of XML file first. IE only. } else if (document.implementation && document.implementation.createDocument) var xmlDoc= document.implementation.createDocument("","doc",null); if (typeof xmlDoc!="undefined") xmlDoc.load("namedata.xml"); //Regular expression used to match any non-whitespace character var notWhitespace = /\S/ function getnames(){ //Cache "messages" element of xml file var nameobj=xmlDoc.getElementsByTagName("list")[0] //REMOVE white spaces in XML file. Intended mainly for NS6/Mozilla for (i=0;i<nameobj.childNodes.length;i++){ if ((nameobj.childNodes[i].nodeType == 3)&& (!notWhitespace.test(nameobj.childNodes[i].nodeValue))) { // that is, if it's a whitespace text node nameobj.removeChild(msgobj.childNodes[i]) i-- } } } if (typeof xmlDoc!="undefined"){ if (window.ActiveXObject) //if IE, simply execute script (due to async prop). getnames() else //else if NS6, execute script when XML object has loaded xmlDoc.onload=getnames } var name2=xmlDoc.getElementsByTagName("name")[0].firstChild.nodeValue; var office2=xmlDoc.getElementsByTagName("office")[0].firstChild.nodeValue; var officePH2=xmlDoc.getElementsByTagName("officePH")[0].firstChild.nodeValue; var mobile2=xmlDoc.getElementsByTagName("mobile")[0].firstChild.nodeValue; var email2=xmlDoc.getElementsByTagName("email")[0].firstChild.nodeValue; </script> <script type="text/javascript"> function addOption(selectbox,text,value ) { var optn = document.createElement("OPTION"); optn.text = text; optn.value = value; selectbox.options.add(optn); } </script> Could anyone give me a pointer on how to loop this so that it loads one option after another from the XML file? Thanks. I have the following code which is almost completely working the way I need it to with the exception of the "downloadFile" value... Code: /*Regex list of download file extensions, pipe and backslash delimited. Looks for the period before the file type so it will work on download links with query parameters after it */
var downloadTypes = /\.pdf|\.doc|\.xls|\.zip|\.csv|\.ppt|\.rtf|\.pptx|\.docx|\.xlsx|\.wmv|\.mpg|\.exe|\.mp3|\.rar|\.wav/i;
/*Regex list of on-site domains, pipe and backslash delimited. */
var onsiteDomains = /\mytestdomain1\.com|\mytestdomain2\.com|javascript|#/i;
/*Used to unobtrusivly add events to objects*/
function unobtrusiveAddEvent (element,event,fn) {
var old = (element[event]) ? element[event] : function () {};
element[event] = function () {fn(); old();};
}
var links = document.links;
if ( links ){
for(var i=0; i<links.length; i++) {
if( links[i].href.match(downloadTypes) ){
unobtrusiveAddEvent( links[i], 'onclick' , function() { ntptEventTag('ev=download&eventPage=Download From: ' + escape( wa.currentDomain + wa.currentURL ) + '& downloadFile=' + escape( links[i] ) ); });
}
if( !links[i].href.match(onsiteDomains) ){
unobtrusiveAddEvent( links[i], 'onclick' , function() { ntptEventTag('lk=1&ev=Exit Link'); });
}
}
}
...how do I grab the value of the href that was just clicked? links[i] is not working (it's just grabbing the href value of the last href in the loop). I am missing something simple for sure. Can anyone point out what I am missing? Thanks! Code: // Values for fading
var fadeBy = 10; //Amount to fade by
var fadeTime = 120; //Time in milliseconds to fade.
var ie_counter = 0; //Counter for crappy IE.
var fade_to = 70;
function fader(obj) {
var div = document.getElementById(obj);
//Object details
var opacity = div.style.opacity * 100 + fadeBy; //Fade (FF)
ie_counter = ie_counter + fadeBy;
var opacity_ie = div.style.filter = "alpha(opacity=" + ie_counter + ")"; //Fade (IE)
div.style.opacity = opacity / 100;
if ( ie_counter != fade_to || opacity != fade_to ) {
setTimeout( "fader('" + obj + "')", fadeTime );
}
}
The loop stops for firefox (good browser), but not for internet explorer for some reason :/ Apart for the fact that IE is crap why is this? |
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