<button onclick="Concat()">Concat</button>
<p id="demo"></p>

<script>
var arr1 = [40, 100, 1, 5, 25, 10];
var arr2 = ['saurabh', 'sharma'];
var arr3 = ['Apple', 'Google',25];

function Concat() {
var concatenated_array = arr1.concat(arr2,arr3);
document.getElementById("demo").innerHTML = concatenated_array;
}

</script>