JavaScript - Passing Arguments

Let's say I'm defining an object and I want the constructor to take one input and ten save it. I'd like to do something like this:

function apple(color) {
this.color = arguments.color;
}

But of course that doesn't work because arguments isn't a scope. My question is, is there a scope I can use. What I've been doing instead is this:

function apple(new_color) {this.color = new_color;}

But that just seems less than perfectly pretty.

I want to use the new keyword to instantiate an object. The catch is I want to pass in variable length arguments.

Given:
Code:

function Foo () {
  this.args = Array.prototype.join.call (arguments);
}

var args = ["arg0", "arg1", "arg2"];

The following don't work (though I understand why):
Code:

new Foo.apply (null, args);

new (Foo.apply (null, args));

(new Foo).apply (null, args);

Any ideas on how to do what I want without modifying Foo's source code?

Hello, i'm working on a 3 page survey. When hitting next, previous, or submit it passes the values of all the questions to the next page. I've got the whole thing working correcting except for one thing: When the box is "not" checked it passes no value. I'm needing it to have a value of "1" when checked and a value of "0" when not checked, and currently when its not checked and i pass the info it leaves it blank.

I'd post the whole code to one of the pages but it's long , so i'll post the snipits of the code.
Code:

<script type="text/javascript"> 
/* <![CDATA[ */
function processQueryString() {
var formData = location.search;
formData = formData.substring(1, formData.length);
while (formData.indexOf("+") != -1) {
	formData = formData.replace("+", " ");
}
formData = unescape(formData);
var formArray = formData.split("&");
for (var i=0; i < formArray.length; ++i) {
	//document.writeln(formArray[i] + "<br />");
	var sDataName = formArray[i].split("=")
	
switch (sDataName[0]) {

case ".lib_use":
     for (var j=0; j < document.getElementsByName(".lib_use").length; ++j) {
     if (document.getElementsByName(".lib_use").item(j).value == sDataName[1]) {
     document.getElementsByName(".lib_use").item(j).checked = true;
     //alert("lib_use set");
              }
 }
 break;
case ".lib_comp":
     if (sDataName[1] == 1) {
     document.getElementsByName(".lib_comp").checked = true;
     document.getElementsByName(".lib_comp").value= 1;
   } 
   else {
    document.getElementsByName(".lib_comp").checked = false; 
   document.getElementsByName(".lib_comp").value= 0;
 }			 
 break;	
default:
      alert("not caught = " + sDataName[0]);
       continue;
		
	}
}
}
/* ]]> */
</script>

<input type="checkbox" name=".lib_comp" id="lib_comp" value="1" />

The first case that i showed in my code is a radio button, and it passes correctly, i just wanted to show the "format" i was using in a working sense. The 2nd case is an example of the check boxes.

Thanks for looking at this, and giving any suggestions you might have!

Hi all,

I have a newbie question. I have just started working with javascript and would appreciate some guidance.
I have a webpage and there are products for sale on it(this is not live it is merely being used as practice project). Beside each product is a description a price and an 'add to cart' button.

My cart is simply a div with an id of 'cart' and it has a text box within it. I need the product name to be displayed within the div (this, I have working), I also need to display the product price in the text box once the button(add to cart ) for that particular product has been pressed.
Also when the button for another product is pressed, I want the cost/value for that product to be added to the other value and displayed in the text box in the cart div...

I apologise for rambling on but this is the best way of me explaining my needs....

Here's where i am right now..
The HTML snippet

Code:

<div id ="cart">
    		<p><img src="images/shopping-cart.png"  alt ="cart"/>Your Cart</p>
            
            	<div id="sum"><!--(this is the div where the total goes)-->
					<input type="text" id="total" value="0" /><p>&euro;&nbsp; Your Total &nbsp;<input type="reset" value = "reset" /></p>
                 </div>
    	</div>

<h2 id ="black">Blackcurrent<br /></h2>
        <p>&euro; 12.00 <input type = "submit" value ="add to cart"  onClick = "shoppingCart('Blackcurrent',12)" /></p>

And the javascript:

Code:

alert ("working");

function shoppingCart (itemName,itemValue)
{
/*	var thePrice = Number(itemValue);
	return thePrice;*/
	document.getElementById ("cart").innerHTML += itemName  + "<br/>";
	document.getElementById('total').value = Number(document.getElementById('total').value) + itemValue;
	
		
}

I hope i have posted correctly and am aware that i have only posted a segment of the HTML..

Please let me know if you need any more code or info..

Thanks a lot in advance for any help...

Code:

<html>
<head>
<title>Variable - Examples 1</title>
   <script type="text/javascript">
	function Student(firstName, lastName, email, courseID, titleArray, pointsArray){
		this.firstName = firstName;
		this.lastName = lastName;
		this.email = email;
		this.courseID = courseID;
		this.title = titleArray;
		this.points = pointsArray;
 		this.assign = this.points.slice(0,4);
		this.exams = this.points.slice(-2); 
		this.assignments = function() { return task(this.title,this.points); }
		this.totalPoints = function() {return addExam(this.assign,this.exams); }
		this.finalGrade = calcGrade;
	}
	
	Student.prototype = {
		constructor : Student,
		toString : studentInfo
	};
	
 //assign and exam doesn't seem to hold no values inside.. ???	 
 	function addExam(assign,exams){
		var exams=this.exams;
		var high1=exams[0];
		var high2=0;
		while(high2<exams.length){
			high1=Math.max(high1,exams[high2]);
			high2++;
		}
		var sum = 0;
		for (var i=0; i < assign.length; i++){
			sum += assign[i];
		}
		return sum + high1;	
	} 
	var totalPoints = addExam();
	
	function calcGrade(){
		var grade;
		if (totalPoints >= 190){
			return "A+";
		}else if (totalPoints >= 180){
			return "A";
		}else if (totalPoints >= 175){
			return "B+"
		}else if (totalPoints >= 170){
			return "B";
		}else if (totalPoints >= 165){
			return "B-";
		}else if (totalPoints >= 160){
			return "C";
		}else if (totalPoints >= 150){
			return "D";
		}else if (totalPoints < 150){
			return "F";
		}
	}
	
	function studentInfo(){
			 return "Student : " + this.lastName + "," + this.firstName + "<br>"+ "eMail : " + this.email + "<br>" + "Course ID : " + this.courseID + "<br>" + "--------------------------------" + "<br>" + this.assignments() +  "--------------------------------" + "<br>" + "Total Points : " + this.totalPoints() + "<br>" + "Final Grade : " + this.finalGrade();
	}
	
 	function createStudents(){
		var student1 = new Student("Jake", "Hennry", "jhennery@gmail.com","COIN-070B.01", ["Assignment1","Assignment2","Assignment3","Assignment4","Assignment5","MidTerm", "Final"], [25, 25, 28, 20, 29, 40, 40] );
		alert("Student : " + student1.lastName + "," + student1.firstName + "\n"+ "eMail : " + student1.email + "\n" + "Course ID : " + student1.courseID + "\n" + "---------------------------------------" + "\n" + student1.assignments() +  "\n" + "---------------------------------------" + "\n" + "Total Points : " + student1.totalPoints() + "\n" + "Final Grade : " + student1.finalGrade());
	}
	 
	var titleArray = ["Assignment1","Assignment2","Assignment3","Assignment4","Assignment5","MidTerm", "Final"];
	var pointsArray = [30, 30, 28, 27, 29, 41, 45];
	var student = new Student("Haripriyaa", "Ganesan", "haripriyaa@gmail.com","COIN-070B.01", titleArray, pointsArray );
   </script>
</head>
<body>
	<script type="text/javascript">    
		document.writeln(student.toString());
	</script>
</body>
</html>

Dear all,

I'm passing the variables myTitle and myLink to form.php using javascript.
This is the way I'm doing it:

Code:

<a href='form.php?title=" + myTitle +"&link="+myLink+">Click me</a>

It's working great but sometimes myTitle and myLink contain the plus character (+). When this happens it's not passed. In the case of the title, it's just a problem of looks but in the case of the link, well, the link won't work without the character.

As an example if the title is: Laptop + Accessories
What is passed is: Laptop Accessories

What can I do to pass also the plus character??
Thanks a lot!!

Hi,

I have what I assume started as a simple error and then trying to fix it I think I have made things so complicated I've become confused. I have two fields, a drop down list and a text field, when someone clicks on a value in a drop down list (I will show the results eventually but at the moment) I just want the result to echo in my getCategory.php and the same for the text field. Both php pages are currently being called. And at the moment contain $_REQUEST['category'] and $_REQUEST['ProductName'] respectively. Nothing is being echoed.

I know the below code is wrong, but the more I try to correct it the worse it gets so I thought I would just leave it as is before I made it worse.

Code:

<script type="text/javascript">
function loadXMLDoc1(File,ID,Msg){
if (window.XMLHttpRequest)  {
  xmlhttp=new XMLHttpRequest();
  }
else {
	try{
  xmlhttp=new ActiveXObject("Msxml2.XMLHTTP");
  } catch (e) {
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
  }	
}

xmlhttp.onreadystatechange=function(){
  if (xmlhttp.readyState==4 && xmlhttp.status==200){
    document.getElementById(ID).innerHTML=xmlhttp.responseText;
    }
  }

var params=Msg;
xmlhttp.open("POST",File,true);

xmlhttp.setRequestHeader("Pragma", "Cache-Control:no-cache");
xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
xmlhttp.setRequestHeader("Content-length", params.length);
xmlhttp.setRequestHeader("Connection", "close");
xmlhttp.send(params);
}

</script>
</head>
<body>
<label>Search by Category: </label>
<select name="category" id="category" onchange='loadXMLDoc1("getCategory.php","txtHint","category")' class="input">
<option value="please select"
selected"selected">Please Select</option>
<option value="Clothes" name="Clothes" id="Clothes">Clothes</option>
<option value="Bags" name="Bags" id="Bags">Bags</option>
<option value="Hats" name="Hats" id="Hats">Hats</option>
</select>
	<br />
<br />
<label>Search by name: </label>
<input type="text" class="input" name="ProductName" id="ProductName" value="Search" size="30"/>&nbsp<input type="button" value="Search" onclick="loadXMLDoc1('getProductName.php','txtHint', ProductName='(this.value)')" />
	<br />
	<br />
<div id="txtHint"></div>

Hi,

I've had problems in the past understanding this, however, after reading this tutorial, I understand. In some languages, like VB6, I notice the "byVal" and the "byRef" is specifically used. In javascript, I don't notice those specifics typed in functions. Is the "default" by value when using in a function to change a parameter? If it is, what is the syntax for using by reference, or is that ever used?

My question arises from this notation taken from here:

Quote:
Note that it is the value that a has at the time that it is passed into the function that gets substituted into the argument and not the value that the original variable has at that point in the processing. It is the values in the parameters that the function uses and not the variables. This is called pass by value . In those languages where you can pass the actual variable into the function instead of just passing its value the method used to do so is called pass by reference . Had we been able to pass the variables into the function by reference rather than by value then the final value in b would have been -16 instead of -14.
Here is the example (passing by value):

Code:

function myfunction(y, z) {
  a += y;
  b -= z;
}


var a = 0;
var b = 10;
var c = 3;
var d = 4;
var e = 2;
myfunction(c, d);
myfunction(d, e);
myfunction(9, 2);
myfunction(b, a);

Results:
myFunction(c, d);	output:  0 +  3 = 3(y), 10 - 4 = 6(z)
myFunction(d, e);	output:  3 +  4 = 7(y),  6 - 2 = 4(z) 
myFunction(9, 2);	output:  7 +  9 = 16(y), 4 - 2 = 2(z)
myFunction(b, a);	output:  2 + 16 = 18(y), 2 -16 = -14(z)

Thanks!

Can anyone put into "simple" words the purpose of arguments in JS please?

I've had some help figuring out how to pass a variable through a pop-up window:

Code:

<script type="text/javascript">
function expo(o) {
  var et = document.getElementById(o);
  if(et) {
    window.open( "exp.php?exportthis="+et.value, "myWindow", "status = 1, height = 300, width = 300, resizable = 0");
  }
}
</script>


<form action="" method="post"><input type=hidden value="$file" name="exportthis" ><input type=submit value=Export name= "Exp"onclick="expo('exportthis');" />
</form>

However, my issue is that I have multiple forms. The forms are the same - the variables are different. The code above only works with the first variable returned. Here's an example of the problem.

Code:

<?PHP 

//for example purposes the filename will be labeled as numbers
$i = 1;

while ($i < 5) {
echo "<form action=\"\" method=\"post\"><input type=hidden value=\"$i\" name=\"exportthis\" ><input type=submit  value=\"Export\" name= \"Exp\"onclick=\"expo('exportthis');\" /></form>";
}
?>

The above simple PHP script produces 5 simple forms. All of them are identical with the exception of the 'exportthis' or variable that I'm trying to pass through. They are numbered '1' to '5'. If I press the submit button for any of them only the first variable (in this case '1') is passed through.

Can someone help me modify the javascript so that the right variable is passed through and not just the first one?

Hi, I am trying to pass data from one page to the next using a search. I have a search engine and im trying to get it to pass the data of the search to the search results page. im using this code Code:

<script type="text/javascript">
	window.onload = function (){ try{document.getElementById('q').focus();}catch(e){} }
	
	function search()
	{
		var search_text = document.getElementById('q').value;
		window.location = '/search/'+encodeURI(search_text)+'/';
		return false;
	}
</script>

and I am using this for the search
Code:

	<form action="/search/" method="post" onSubmit="return search();">
		<input type="text" id="q" name="q" value="" class="searc" style="width:350px; height:30px; font-size:18px; color:#C19051" />
		<input type="submit" style="height:30px;" value="Search" class="submit"/>
	</form>

Can anybody help me with this? Thanks

Is it possible to pass the id onChange like in this example instead of the value

This is part of a large complex script, and I need the id as seperate function

Code:

<select name='color' onChange='this.form.F1.value=this.form.color.id' >
<option value='Green' id='c1'>Green
<option value='Red'   id='c2'>Red
<option value='Blue'  id='c3'>Blue
</select>

<input type="text" name="F1" size="15" value="" onChange="this.value=this.form.color.id">

Hello Guys,

I have a page with thumb nails and a large image that changes when clicking on thumbnail. I need to display dynamic title for the image. It wont display because the page is not reloading.. How do you pass the name so it will show up without reloading?

Here is the JS for switching dynamically loading the large image

PHP Code:
<script language="javascript">
$(document).ready(function() {
    $('.thumbnail').live("click", function() {
        $('#mainImage').hide();
        $('#atitle').hide();
        $('#imageWrap').css('background-image', "url('/images/ajax-loader.gif')");
        var i = $('<img />').attr('src',this.href).load(function() {
            $('#mainImage').attr('src', i.attr('src'));
             $('#imageWrap').css('background-image', 'none');
            $('#mainImage').fadeIn();
             $('#atitle').fadeIn();
            
           
        });
        return false; 
    });
});
</script> 


Here is the link for the thumb

PHP Code:
  // Thumbnail Display
                 
                 echo '<a href="artists/'.$artist.'/'.$imgname.'.jpg" class="thumbnail"><img src="artists/'.$artist.'/previews/'.$imgname.'.jpg" border="0" /></a>'; 


[/PHP]

Link to the large image

PHP Code:
  // Large image display              
                            echo '<img src="artists/'.$artist.'/'.$first_image.'.jpg" alt="Main Image" id="mainImage"/>'; 


Here is the php echo for the title
PHP Code:
<? echo  str_replace('"', '`',  $iname); ?>

I need to some how pass a php var from the thumb link to the js and have it display dynamically(without reloading)

Hope I explained this correctly.. Please advise..

Thanks, Dan

How do I pass an id to a function??
Or is this even possible.

Code:

<html>
<head>
<title>
  JavaScript array passing example
</title>
<script type="text/javascript">

function init(){
   display(addText1);
   display(addText2);
   display(addText3);
   display(addText4);
}

function display(var myText){
  var newText = '<h2>' + "Will this change anything..." + '</h2>';

   document.getElementById('myText').innerHTML = newText;
}
</script>
</head>
<body onload="init()">

<div id="addText1"></div>
<div id="addText2"></div>
<div id="addText3"></div>
<div id="addText4"></div>
</body>
</html>

Code:

function viewDetails(rowid,linkid){
	
	
	alert("enterining into bundles");
	if(linkid=='seobundles')
	{
	alert("enetering into if ");
	document.chwAnnouncementW.action='${contextPath}'+"/dolphin.wss/viewSeobundleW?rowindex="+rowid;
    		document.chwAnnouncementW.submit();
		
		
		
		
		
	
	}

	else
	{

	alert(linkid);	
	document.chwAnnouncementW.action='${contextPath}'+"/dolphin.wss/viewSeoW?rowindex="+rowid;
    		document.chwAnnouncementW.submit();
	}
	
	
}

Actually i am passing linkid="seobundles" as string but its not interpreting and it is always going to else part and not if part. I tried to print link id its teling its of object HTML table type and we are passing the two parameters rowid, linkid from a macro. rowid is working fine as and when we select radio buttion but linkid is not working as an string. IF i pur linkid in single quotes then also its not working