Menu
In the below code,
<!DOCTYPE html>
<html>
<head>
<title>Hide odd rows</title>
<meta charset="UTF-8">
</head>
<body>
<div style="background-color:#8F9779;width:200px;height:30px;">
</div>
<hr style="width:200px" align="left">
<table border="1" >
<tr class="hide" >
<td width="40" height="20">row 1</td>
</tr>
<tr>
<td width="40" height="20">row 2</td>
</tr>
<tr class="hide">
<td width="40" height="20">row 3</td>
</tr>
<tr>
<td width="40" height="20">row 4</td>
</tr>
<tr class="hide">
<td width="40" height="20">row 5</td>
</tr>
</table><br>
<button type="button" name="HideRows">Hide Odd Rows</button>
<script type="text/javascript" src="hideOddRows.js"></script>
</body>
</html>
/* hideOddRows.js */
document.querySelector('[name=HideRows]').onclick = hideRows;
function hideRows(){
var elements = document.getElementsByClassName('hide');
elements.forEach(function(element){
element.style.visibility = "hidden";
});
return true;
}
As per debugging, callback function for each element of elements array is not executing on click event.
I consider elements as keyed collection, as shown below..
--
How to resolve this error?
577
forEach is not included in the prototype of the array-like HTMLCollection object returned by getElementsByClassName.
An HTMLCollection instance is array-like, in that you can access elements by indexes, but it does not include all of the methods of an array, as you have discovered with forEach.
You can however manually call the method on the object by accessing the method from the Array prototype.
var elements = document.getElementsByClassName('hide');
Array.prototype.forEach.call(elements, function(element){
element.style.visibility = "hidden";
});
The forEach method is for arrays. It's not working because .getElementsByClassName() returns an HTMLCollection.
To work around this, use:
var elements = document.getElementsByClassName('hide');
Array.prototype.forEach.call(elements, function(element){
element.style.visibility = "hidden";
});
or shorter:
var elements = document.getElementsByClassName('hide');
[].forEach.call(elements, function(element){
element.style.visibility = "hidden";
});
you can convert elements to an array and then call forEach().
var elements = document.getElementsByClassName('hide');
elements = Array.prototype.slice.call(elements,0);
elements.forEach(function(element){
element.style.visibility = "hidden";
});
fiddle :https://jsfiddle.net/assx7hmh/
1
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
