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Elements Object
The elements object (array) allows you to access any element within a form generically, via a loop for example. Each element inside the form is stored as an array element inside elements[]. The syntax is as follows:
document.myform.elements[i] //access the ith form element
within the form
document.myform.elements[i].type //Returns the type of the ith form element (ie:
"textarea")
document.myform.elements.length //Returns the total number of form elements
within form
Properties
Properties | Description | ||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
elements.length | Returns the total number of elements within the form | ||||||||||||||||||||||||||||
elements[i].type | Returns the type of the referenced form element as a
string value (Example):
|
||||||||||||||||||||||||||||
elements[i].property | Apart from "type", all properties available to the accessed form element is also available when accessed via the elements object, such as "name", "value" etc. |
Examples
Form validation- Check "text" and "textarea" fields for user input
This classic example uses the elements object to generically scan a form and makes sure all text boxes and textareas have text entered before allowing the form to submit:
<script type="text/javascript">
function checkempty(theform){
var returnval=true //by default, allow form submission
for (i=0; i<theform.elements.length; i++){
if (theform.elements[i].type=="text" || theform.elements[i].type=="textarea"){
if (theform.elements[i].value==""){ //if empty field
alert("Please make sure all fields are entered") //alert error message
returnval=false //disallow form submission
break //end loop. No need to continue.
}
}
}
return returnval
}
</script>
<form onSubmit="return checkempty(this)">
Name: <input type="text" name="yourname" /><br />
Email: <input type="text" name="email" /><br />
Comments: <textarea name="comments"></textarea><br />
<input type="submit" value="submit" />
</form>
Output:
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