In case you want khổng lồ have sầu a mặc định text as a sort of placeholder/hint but not considered a valid value (something like "complete here", "select your nation" ecc.) you can bởi something lượt thích this:
I came across this question, but the accepted & highly upvoted answer didn"t work for me. It turns out that if you are using React, then setting selected doesn"t work.
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Instead you have khổng lồ mix a value in the tag directly as shown below:
Apple Banamãng cầu CranberryRead more about why here on the React page.
You can bởi vì it like this:
1 2 3 4 5 Provide "selected" từ khoá inside the option tag, which you want khổng lồ appear by mặc định in your drop down các mục.
Or you can also provide attribute lớn the option tag i.e.
if you want to lớn use the values from a Form and keep it dynamic try this with php
/" method="post"> >1 >2
I prefer this:
Choose here One Two Three Four Five"Choose here" disappears after an option has been selected.
Best way in my opinion:
Choose here One Two Three Four FiveWhy not disabled?
When you use disabled attribute together with Rephối value is not rephối lớn original placeholder. Instead browser choose first not disabled option which may cause user mistakes.
Default empty value
Every production size has validation, then empty value should not be a problem. This way we may have sầu empty not required select.
XHTML syntax attributes
selected="selected" syntax is the only way to be compatible with both XHTML and HTML 5. It is correct XML syntax và some editors may be happy about this. It is more backward compatible. If XML compliance is important you should follow the full syntax.
An improvement for nobita"s answer. Also you can improve sầu the visual view of the drop down danh sách, by hiding the element "Choose here".
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(You could use this example to lớn for loop an array of values inkhổng lồ a drop down component)
// Get the select elementvar select = document.getElementById("yourDropDownElementId");// Create a new option elementvar el = document.createElement("option");// Add our value to lớn the optionel.textContent = "Example Value";el.value = "Example Value";// Set the option khổng lồ selectedel.selected = true;// Add the new option element to lớn the select elementselect.appendChild(el);
The selected attribute is a boolean attribute.
When present, it specifies that an option should be pre-selected when the page loads.
The pre-selected option will be displayed first in the drop-down menu.
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If you are using select with angular 1, then you need to lớn use ng-init, otherwise, second option will not be selected since, ng-model overrides the defaul selected value
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I used this php function to generate the options, & insert it inkhổng lồ my HTML
" . sprintf($formatstring,$i) . " "; } return $retstring; }?>And then in my webpage code I use it as below;
If $endmin is created from a _POST variable every time the page is loaded (& this code is inside a size which posts) then the previously selected value is selected by mặc định.
value attribute of tag is missing, so it doesn"t show as u desired selected. By default first option show on dropdown page load, if value attribute is set on tag.... I got solved my problem this way
This code sets the default value for the HTML select element with PHP..
". $nr .""; } else emang lại "". $nr .""; $nr++; }?>
I would just simply make the first select option value the default and just hide that value in the dropdown with HTML5"s new "hidden" feature. Like this:
Select An Option One Two Three Four
You just need lớn put attribute "selected" on a particular option instead direct to select element.
Here is snippet for same and multiple working example with different values.
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The problem with is, it"s sometimes disconnected with the state of what"s currently rendered & unless something has changed in the option menu, no change value is returned. This can be a problem when trying to lớn select the first option from a danh sách. The following code can get the first-option the first-time selected, but onchange="changeFontSize(this)" by its self would not. There are methods described above using a dummy option to force a user to lớn make a change value khổng lồ pickup the actual first value, such as starting the menu with an empty value. Note: oncliông xã would Hotline the function twice, the following code does not, but solves the first-time problem.
Font Size Small Medium Large Extra large
I use Angular and i phối the default option by
test1 test2 Script:
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The function first tries to lớn find the with the id, then it will tìm kiếm for the value_selected in the options & if it finds it, it will phối the selected attribute returning true. False otherwise
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How vì chưng you remove sầu all the options of a select box and then add one option and select it with jQuery?
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