To delete an element from a JavaScript array, firstly use the indexOf() method to get the index of the element to be deleted. After that use splice() method −
Example
<html>
<body>
<script>
var array = [40, 20, 70, 50];
var index = array.indexOf(70);
document.write("Original array: "+array);
if (index > -1) {
array.splice(index, 1);
}
document.write("<br>New array after deletion: "+array);
</script>
</body>
</html>Output
Original array: 40,20,70,50 New array after deletion: 40,20,50