JavaScript automatic comma

In my program, the user enters values betweeen 0 and 8.

For example: if the user wants to input “3,4” he only needs to write “34”. the program will eventually put the comma in, but I have no clue how to do it.

So:

• input = “34” –> output = “3,4”

• input = “09” –> output = “0,9”

This is what i tried, but of course it will accept “34” as integer:

function numberWithCommas(x) {
    return x.toString().replace(/B(?=(d{3})+(?!d))/g, ",");
}

I also tried to split the input, but when the user inputs a integer like 3, it doesn’t work anymore.

There’s no deeper meaning to this problem, but to make the user input faster.

Answer

You should:

1. Convert the input number to a string (toString);
2. Split the string between each character into an array (split);
3. Join the elements of this array, separated by , (join).

Here you are the full code:

function numberWithCommas(x) {
    return x.toString().split("").join(",");
}