I have a pre defined string as Follows.

```
string preDefined="abc"; // or i can use char array in here
string value="ac";
string value1="abw";

```

I need some function to compare value with preDefined.

```
 (value.SomefunctionContains(preDefined) 

```

this function needs to return 

```
value -> true;
value1 -> false

```

I knew that i can't use contains() or Any(). so plz help