Javascript Filter() Function

The every() method of array object tests whether all elements in the array pass the test implemented by the provided function. The filter method of array object will creates a new array with all of the elements of this array for which the provided filtering function returns true. Use it for example to test each element of the array.

Syntax

arr.filter(callback[, thisArg])

Javascript Filter() Function Example1

<html>
<head>
<script type="text/javascript">
function checkGreaterThanTwoDigit(array_element) {
  return array_element >= 20;
}
var filtered = [42, 5, 8, 330, 144].filter(checkGreaterThanTwoDigit);
document.write(filtered);

</script>
</head>
<body>
</body>
</html>

This will produce following result

[42, 330, 144]

Javascript Filter() Function Example2

<html>
<head>
<script type="text/javascript">

function checkNumberRange(value) {
    if (typeof value !== 'number')
        return false;
    else 
        return value >= this.minimum && value <= this.maximum;
}

var some_numbers = [6, 12, "101", 16, "you", -11,-22];

// The obj argument enables use of the this value
// within the callback function.
var obj = { minimum: 10, maximum: 100 }

var result = some_numbers.filter(checkNumberRange, obj);

document.write(result);

</script>
</head>
<body>
</body>
</html>

This will produce following result