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JavaScript jQuery Basics (2014) Creating a Mobile Drop Down Menu Perform: Part 3

Posted by Iliya Narsiya
Iliya Narsiya
3,387 Points

My question about method prop()

var $select = $("<select></select>");
$("#menu").append($select);

$("#menu a").each(function(){
var $anchor = $(this);
var $option = $("<option></option>");

if ($anchor.parent().hasClass("selected") ){
$option.prop("selected",true);

}   


$option.val($anchor.attr("href"));    

$option.text($anchor.text());
$select.append($option);
});

var $button = $("<button>Go</button>");
$("#menu").append($button);
$button.click(function(){


window.location = $select.val();    

});

Why here in the part code stated value true? $option.prop("selected",true);

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

By the way, I edited your post to add in code formatting. Take a look at how to do this yourself: click on the edit button below your post and click edit. You'll see the markup I added.

2 Answers

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Hi Iliya,

I'm not sure I completely understand your question, but you can find the documentation for the prop() method, and this specific version of it here. Essentially, you're setting the property "selected" to true. If you put false in there, it would remove the property "selected" from the html.

Here's the javascript and resultant html:

script.js 
$option.prop("selected", true);

leads to:

main.html 
<option selected></option>

whereas:

script.js 
$option.prop("selected", false);

leads to:

main.html 
<option></option>

Let me know if this answers your question!

-Greg

Iliya Narsiya
Iliya Narsiya
3,387 Points

But if remove value true, code will be work also .

Iliya Narsiya
Iliya Narsiya
3,387 Points

thank you very much for your help!

Niclas Valentiner
Niclas Valentiner
8,947 Points
Niclas Valentiner
Niclas Valentiner
8,947 Points

$option.prop("selected",true); This sets the selected property of $option to true.

Iliya Narsiya
Iliya Narsiya
3,387 Points

why he is set?

Ryan Field
Ryan Field
Courses Plus Student 21,242 Points
Ryan Field
Ryan Field
Courses Plus Student 21,242 Points

It is being set because that is how you make a certain option selected in a dropdown (or select menu). If you are unaware of how such menus work, there is more information here.

Iliya Narsiya
Iliya Narsiya
3,387 Points

Ryan Field thank you! Now i all understood!