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>