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.
1. `if(strlen(str) == 0)` -> it will **crash** if `str==NULL` (you need to check it before you use `strlen`)
2. `if(str[0] != 0)` -> the same as above
3. `if(!*str)` -> this is actually doing the same thing as **2)**

To summarise: if you want to do it safely:

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

```