<html>
<body>
<p id="demo">Click the button to create an array, call the new ucase() method, and display the result.</p>
<button onclick="myFunction()">Try it</button>
<script>
Array.prototype.myUcase=function()
{
for (i=0;i<this.length;i++)
{
this[i]=this[i].toUpperCase();
}
}
function myFunction()
{
var fruits = ["Banana", "Orange", "Apple", "Mango"];
fruits.myUcase();
var x=document.getElementById("demo");
x.innerHTML=fruits;
}
</script>
</body>
</html>