ECMAScript5 provides a map method for Arrays, applying a function to all elements of an array. Here is an example:

var a = ['1','2','3']
var result = a.map(function (x) { 
  return parseInt(x, 10); 
});

console.log(result);

See Array.prototype.map()

try with

+Arr[0].replace(/\D/g, '');

Example fiddle: http://jsfiddle.net/t6yCV/

Starting + is working like parseInt() and it is necessary if you need to perform some mathematical operation with the number obtained: in fact

typeof Arr[0].replace(/\D/g,'')  // String
typeof +Arr[0].replace(/\D/g,'') // Number

An easier method is to map to the Number object

result= stringBits.map(Number); 

You can use Array.map to convert each element into a number.

var a = "1,2,3,4";

var b = a.split(',').map(function(item) {
    return parseInt(item, 10);
});

Check the Docs

Or more elegantly as pointed out by User: thg435

var b = a.split(',').map(Number);

Where Number() would do the rest:check here

Note: For older browsers that don't support map, you can add an implementation yourself like:

Array.prototype.map = Array.prototype.map || function(_x) {
    for(var o=[], i=0; i<this.length; i++) { 
        o[i] = _x(this[i]); 
    }
    return o;
};

From MDN's reference page for parseInt():

The parseInt function converts its first argument to a string, parses that string, then returns an integer or NaN.

If we then look at the MDN reference section on string coercion:

Objects are first converted to a primitive by calling its @@toPrimitive (with "string" as hint), toString(), and valueOf() methods, in that order. The resulting primitive is then converted to a string.

So let's see the result of calling toString() on ['123']:

const arr = ['123'];
const converted = arr.toString();
console.log(converted);
console.log(typeof converted);

It's just the string "123", which, when passed as parseInt("123"), works as expected.

console.log(parseInt("123"));

That said, being cute with automatic type coercion in JS is a dangerous game; it's generally better to be explicit.