Question: Is it possible to edit the text within a cell in datatables. So that when the user double clicks on the cell it becomes editable ?

Thanks

Answer: 
No. I've seen all three. Personally, I use 

```
if (!str[0])

```

Using strlen is a waste of processor time and not safe unless you can guarantee the string is terminated.
If you already know that `str` is non-null:

```
if (!*str) {
    // empty string
}

```

Otherwise:

```
if (!str || !*str) {
    // empty string
}

```

Forget about `strlen()`.