Javascript Course

In this page it is presented a JavaScript function that can be used to get the values of the selected (checked) checkboxes added into a form. The function receives the object with that form, then, returns an Array with the value of each selected /checked checkbox into that <form>

Code of the function

// Returns an array with values of the selected (checked) checkboxes in 'frm'
function getSelectedChbox(frm){
 // JavaScript & jQuery Course - https://coursesweb.net/javascript
 var selchbox =[]; // array that will store the value of selected checkboxes

 // gets all the input tags in frm, and their number
 var inpfields = frm.getElementsByTagName('input');

 // traverse the inpfields elements, and adds the value of selected (checked) checkbox in selchbox
 for(var i=0; i<inpfields.length; i++) {
 if(inpfields[i].type =='checkbox' && inpfields[i].checked == true) selchbox.push(inpfields[i].value);
 }

 return selchbox;
}

Example usage getSelectedChbox() function. When click on a button into a form with various checkboxes, it opens an alert window with the values of the selected checkboxes.
<h4>Example getting value of the selected checkboxes</h4>
<p>Select some checkboxes, then click the Click button.</p>

Check the web site programming language you know:
<form action='script.php' method='post'>
<input type='checkbox' name='chb[]' value='html' />HTML<br>
<input type='checkbox' name='chb[]' value='css' />CSS<br>
<input type='checkbox' name='chb[]' value='javascript' />JavaScript<br>
<input type='checkbox' name='chb[]' value='php' />php<br>
<input type='checkbox' name='chb[]' value='python' />Python<br>
<input type='checkbox' name='chb[]' value='net' />Net<br>
<input type='button' value='Click' id='btntest' />
</form>

<script>
// Returns an array with values of the selected (checked) checkboxes in 'frm'
function getSelectedChbox(frm){
 // JavaScript & jQuery Course - https://coursesweb.net/javascript
 var selchbox = []; // array that will store the value of selected checkboxes

 // gets all the input tags in frm, and their number
 var inpfields = frm.getElementsByTagName('input');

 // traverse the inpfields elements, and adds the value of selected (checked) checkbox in selchbox
 for(var i=0; i<inpfields.length; i++){
 if(inpfields[i].type =='checkbox' && inpfields[i].checked == true) selchbox.push(inpfields[i].value);
 }

 return selchbox;
}

 /* Test this function */
// When click on #btntest, alert the selected values
document.getElementById('btntest').onclick = function(){
 var selchb = getSelectedChbox(this.form); // gets the array returned by getSelectedChbox()
 alert(selchb);
}
</script>

Daily Test with Code Example

HTML
CSS
JavaScript
PHP-MySQL
Which type of <input> creates a date input control, such as a pop-up calendar?
type="text" type="date" type="button"
<input type="date" name="set_date" value="2012-10-15" />
Which CSS property adds shadow effects to the text of an element?
font-style color text-shadow
h2 {
  text-shadow: 2px 3px 3px #a0a1fe;
}
Click on the function that adds new elements to the end of an array.
pop() shift() push()
var pags = ["lessons", "courses"];
pags.push("download", "tutorials");
alert(pags[2]);            // download
Which function sorts an array by key, in ascending order, maintaining key to data correlations?
asort() ksort() sort()
$lang =[10=>"PHP", 20=>"JavaScript", "site"=>"coursesweb.net");
ksort($lang);
var_export($lang);     // array ("site"=>"coursesweb.net", 10=>"PHP", 20=>"JavaScript")
Get the value of the selected /checked checkboxes in a form

Last accessed pages

  1. Working with MySQL Database (2265)
  2. Read Excel file data in PHP - PhpExcelReader (90423)
  3. SHA1 Encrypt data in JavaScript (27933)
  4. Courses Web: PHP-MySQL JavaScript Node.js Ajax HTML CSS (125742)
  5. JavaScript Course - Free lessons (29697)

Popular pages this month

  1. PHP Unzipper - Extract Zip, Rar Archives (162)
  2. Courses Web: PHP-MySQL JavaScript Node.js Ajax HTML CSS (99)
  3. SHA1 Encrypt data in JavaScript (78)
  4. Read Excel file data in PHP - PhpExcelReader (74)
  5. Create simple Website with PHP (70)