, I know we can set default option value by using selected in option's attribute.
But Is there any way to set a default value of option from attribute in select tag . i.e when i open page that value should be selected itself , and i want to do this in select tag
Something like this
<select selected= "saab">
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="vw">VW</option>
<option value="audi" >Audi</option>
</select>
No. The only way, in HTML, to set the default option is to use the selected attribute on the option.
This avoids the need to provide id attributes for options (given that multiple options can share the same value) and it also because a select element can have multiple options selected at the same time (if the multiple attribute is set).
Related
In the HTML, I got something like this for select.
What it's doing is the default value showing for the select dropdown is Select year but it cannot be selected.
<select>
<option disabled hidden selected>
Select Year
</option>
<option value="2021">2021</option>
</select>
But when I implement it in React.
It giving me this error
Use the defaultValue or value props on instead of setting selected on .
But when I use default value or value the SELECT YEAR option is not there anymore.
All you need is to remove both selected and disabled attributes from first <option>:
<select>
<option hidden>Select Year</option>
<option value="2021">2021</option>
</select>
Here's why:
<select> is shorthand for <select defaultValue={undefined}>, which makes the first <option> with a value of undefined get selected. In your case, that's the first <option>, since it doesn't have a set value, which is equivalent to having a value set to undefined.
Probably the most important bit is removing disabled. Remember this is JSX, not HTML. JSX is used by React to create valid HTML. If you specify disabled attribute, React won't allow that <option> to be selected, regardless of method.
But you want that <option> selected by default, so it doesn't make sense to disable it.
You only want the user not to be able to select it, which is exactly what the hidden attribute does.
Working demo.
I've made a select in html that looks like this <select name='select' id='select'><option value='val1'>Val1</option><option value='val2'>Val2</option></select>. Is there a way to set the default value of select to something like "pick a value"? Not as an option, but just the text of the select.
You can use the selected attribute within the option to select a default response. If you add the option disabled and hidden then this will be an invalid option.
<select name='select' id='select'>
<option value='val1' selected disabled hidden>Choose option</option>
<option value='val1'>Val1</option>
<option value='val2'>Val2</option>
</select>
Why not just have another option that doesn't have a value and give it the option of selected?
<select name='select' id='select'>
<option value='val1'>Val1</option>
<option value='val2'>Val2</option>
<option value='' selected>Choose Value</option>
</select>
Then in your php or whatever server side test to make sure you aren't accepting an empty value, or use js to not allow the form to submit if the value is blank?
Suppose I have an HTML Form which contains a drop down (and a submit button), through which a user can select any one of the unit of length and submit the form. The code for the drop down menu is show below :
<select name = "from_length">
<option value = "choose_1">Metre</option>
<option value = "choose_2">Kilometre</option>
<option value = "choose_3">Millimetre</option>
<option value = "choose_4">Yard</option>
<option value = "choose_5">Light Year</option>
</select>
I want to select a default option which shall be displayed to the user, when the user opens the webpage.
However, there's a twist. I don't want to use the selected attribute in order to show a default option to the user. This is because the default option being displayed to the user may change depending on certain conditions (for e.g. when user selects "Kilometre" and submits this form, the user must see "Kilometre" selected by default, and not "Metre" (the first option)).
I wish to know if it is possible to select the default value based on the value of the option being selected by the user using only HTML (i.e. no JavaScript)
Thanks in advance for helping me out !
The only way I see that you can do this is with PHP, which allows you to get access to form data. The file extension would also have to be changed from ‘html’ to ‘php’ for this to work.
<select name = "from_length">
<option value="choose_1"<?php if($_POST["from_length"]=="choose_1"){echo(" selected");} ?>>Metre</option>
<option value="choose_2"<?php if($_POST["from_length"]=="choose_2"){echo(" selected");} ?>>Kilometre</option>
<option value="choose_3"<?php if($_POST["from_length"]=="choose_3"){echo(" selected");} ?>>Millimetre</option>
<option value="choose_4"<?php if($_POST["from_length"]=="choose_4"){echo(" selected");} ?>>Yard</option>
<option value="choose_5"<?php if($_POST["from_length"]=="choose_5"){echo(" selected");} ?>>Light Year</option>
</select>
My code still uses the selected attribute, but on each line, the php code checks if this option has been selected by the user, and only if it has, then the 'selected' attribute is printed into the document.
In all browsers that I know of, the first option is selected pr default in the below HTML:
<select>
<option>foo</option>
<option>bar</option>
</select>
But can I count on this behavior? Or would it be better practice to explicit specify default value even when it is the first option, ie would it be safer to go:
<select>
<option selected>foo</option>
<option>bar</option>
</select>
The HTML(5) specification doesn't say that the default selected option should be the first one if no selected attribute is present.
The selectedness of an option element is a boolean state, initially false. Except where otherwise specified, when the element is created, its selectedness must be set to true if the element has a selected attribute. Whenever an option element's selected attribute is added, its selectedness must be set to true.
It does however say that if no selected value is present then the default should be to return a selectedness value of -1.
The selectedIndex IDL attribute, on getting, must return the index of the first option element in the list of options in tree order that has its selectedness set to true, if any. If there isn't one, then it must return −1.
I guess you therefore shouldn't assume that the first option will always be selected as default.
I don't think it matters. It's only if you do not have your default value at the top. The "selected" is if you want to change the default option. If you don't have it on the top.
Like this:
<select>
<option value="volvo">Volvo</option>
<option value="saab">Saab</option>
<option value="vw">VW</option>
<option value="audi" selected>Audi</option>
</select>
On first render (or perhaps when the <select> element is created), the first <option> is implicitly selected: selectedIndex returns 0, and selected (of first option) returns true.
But if you change the options with JavaScript, for example remove all options and add new ones, then selectedIndex returns -1, and selected (of first option) returns false.
All the above assumes, of course, that the selected="selected" attribute is never used.
So, if you are dynamically adding options, and want to make use the first is initially selected, then you must use the selected attribute.
How to get the first value to be default value. In the select option values I have taken a loop for the multiple values. Now I want to select the first values by default but in a way that the last value is always selected by default. How do I do this?
try <option value="1" selected="selected">xyz</option>
use selected attribute for your first option
Try this, add the selected attribute to the option u want to be selected
<select>
<option selected="selected" value="1">selected option1</option>
<option value="2">option2</option>
<option value="3">option3</option>
</select>