How can I add a character to a random space of a string with JavaScript?

Question

I have a string: The quick brown fox jumped over the lazy dogs. I want to insert a , (comma and space) into a random spot where there currently is just a (space). How can I accomplish this?

Answer 1

Another way:

var string = 'The quick brown fox jumped over the lazy dogs.',
    array = string.split(' '),
    i = Math.random() * (array.length - 1) | 0;

array[i] += ',';
string = array.join(' ');
document.write(string);