Question: ```
Str.replace(',','','');

```

I have to replace `(,)` with `(',')`

but in replace function we have to pass character in `' '` so it is giving me an error.

Answer: 
[String.Replace](http://msdn.microsoft.com/en-us/library/System.String.Replace%28v=vs.80%29.aspx) has 2 overloads, one accepts `char` and one accepts `string` so you can do this:

```
var value = existing.Replace(",", "','");

```
You don't have to pass characters in '' (as characters), you can also pass them as strings using "". That should solve your problem.

```
Str.Replace(",", "','");

```