split string in two on given index and return both parts

Question

I have a string that I need to split on a given index and then return both parts, seperated by a comma. For example:

string: 8211 = 8,211
        98700 = 98,         


        

Answer 1

Try this

function split_at_index(value, index)
{
 return value.substring(0, index) + "," + value.substring(index);
}

console.log(split_at_index('3123124', 2));