:input, :checked and :selected selectors make working with web forms incredibly easier, really.
You know, sometimes while filling out a form, you wonder, ‘Was this option selected, or did I select it?’ That’s where these selectors come into play. I often use them in my own programs, especially when I want the user interface to be dynamic.
It’s especially important to know which options have been checked or selected when collecting information from the user. With these selectors, you can access this information very quickly and practically using JavaScript. It used to be more cumbersome, I suppose, but now, thanks to technology, things have become quite easier.
Let’s start with the :input selector. It broadly covers almost all input elements in forms. Text boxes, buttons, checkboxes, radio buttons, select boxes… all fall under this category. That means, if you want to catch all input elements in a form, just use the :input selector. It provides an excellent starting point to narrow down your selections. For example, when you want to clear all fields in a form, you can select all with :input and then perform the clearing operation. Pretty practical, right?
Now, let’s talk about the :checked selector. It is especially useful for checkboxes and radio buttons. If you want to find out whether a checkbox is checked or which radio button in a group is selected, using :checked gives you the result immediately. This will also be very helpful during form validation. For instance, if a user hasn’t checked an option, you can warn them. This way, you improve user experience, isn’t that great?
There is also the :selected selector. It is used to target the currently selected
So, how do we use these? Here, some JavaScript comes into play. You can use these selectors with libraries like jQuery or directly with JavaScript’s querySelectorAll method. I usually prefer jQuery because its syntax is shorter and more readable to me. But, results can also be very good using pure JavaScript, although it may require a bit longer code.
Imagine a scenario: We have a form and we want to find the checked checkboxes and selected radio buttons, then display their values. These selectors really save the day. Coding it out looks like this:
First, let’s look at HTML structure:
<form id=\"myform\"> <div> <input type=\"checkbox\" id=\"option1\" name=\"option1\" value=\"val1\"> <label for=\"option1\">Option 1</label> </div> <div> <input type=\"radio\" id=\"radioA\" name=\"radioGroup\" value=\"A\"> <label for=\"radioA\">Group A</label> <input type=\"radio\" id=\"radioB\" name=\"radioGroup\" value=\"B\"> <label for=\"radioB\">Group B</label> </div> <button type=\"button\" id=\"submitBtn\">Show Values</button> <p id=\"result\"></p> </form>Now, let’s write JavaScript using these selectors to get the checked values. By the way, in my older codes, I sometimes used individual selectors like input[type=’checkbox’], but using :input to encompass all is more logical, thinking about it now. Let’s continue:
$(\"#submitBtn\").click(function() { let resultText = \"\";
// Find checked checkboxes $(\"#myform input[type='checkbox']:checked\").each(function() { resultText += \"Checked Checkbox: \" + $(this).val() + \"<br>\"; });
// Find checked radio button let selectedRadio = $(\"#myform input[type='radio']:checked\").val(); if (selectedRadio) { resultText += \"Checked Radio: \" + selectedRadio + \"<br>\"; } else { resultText += \"No radio selected.<br>\"; }
// If a select dropdown existed... // let selectedOption = $(\"#myform select option:selected\").val(); // if (selectedOption) { // resultText += \"Selected Option: \" + selectedOption + \"<br>\"; // } else { // resultText += \"No option selected.<br>\"; // }
$(\"#result\").html(resultText); });
As you can see, using :checked we easily target the checked elements. If there was a select dropdown, we could target it with :selected. These selectors make accessing form data during collection or validation much cleaner and clearer. It used to be more complicated, needing to manually check each item.
Besides, these selectors can be combined with :input for more powerful filtering. For example, to get all input elements in a form and filter only the checked ones, you can select all with :input first, then filter with :checked or :selected. This speeds up handling complex forms greatly.
Actually, these selectors are also used in CSS. For instance, you can change the style of a label linked to a checkbox when that checkbox is checked by writing a CSS rule like :checked + label. This enables styling based on form elements' states using CSS, not just data retrieval. So, you can create visually dynamic interfaces along with functional ones. How cool is that?
In conclusion, learning and using these three selectors (:input, :checked, :selected) when working with web forms will save you time and make your code more readable. Especially for beginners, manipulating forms with these selectors can be very motivating. If you'd like to learn more, you can do a simple search on Google or find video tutorials on YouTube.
I hope you find this information useful. I keep learning new things about these topics, and sharing my experiences is always enjoyable. :)