How to split a comma separated string and process in a loop using JavaScript

My two cents, adding trim to remove the initial whitespaces left in sAc's answer.

var str = 'Hello, World, etc';
var str_array = str.split(',');

for(var i = 0; i < str_array.length; i++) {
   // Trim the excess whitespace.
   str_array[i] = str_array[i].replace(/^\s*/, "").replace(/\s*$/, "");
   // Add additional code here, such as:
   alert(str_array[i]);
}

Edit:

After getting several upvotes on this answer, I wanted to revisit this. If you want to split on comma, and perform a trim operation, you can do it in one method call without any explicit loops due to the fact that split will also take a regular expression as an argument:

'Hello, cruel , world!'.split(/\s*,\s*/);
//-> ["Hello", "cruel", "world!"]

This solution, however, will not trim the beginning of the first item and the end of the last item which is typically not an issue.

And so to answer the question in regards to process in a loop, if your target browsers support ES5 array extras such as the map or forEach methods, then you could just simply do the following:

myStringWithCommas.split(/\s*,\s*/).forEach(function(myString) {
    console.log(myString);
});

Like this:

var str = 'Hello, World, etc';
var myarray = str.split(',');

for(var i = 0; i < myarray.length; i++)
{
   console.log(myarray[i]);
}