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# Why is the for loop code not running and giving error message?

What is making the code below to give this error: FrogStats.cs(10,17): error CS0019: Operator `+=' cannot be applied to operands of type`double'

class FrogStats { public static double GetAverageTongueLength(Frog[] frogs) { double sum = 0.0; for (int i = 0; i < frogs.Length; i++) { sum += frogs[i];

```            return sum / (frogs.Length);
}
}
}
```
FrogStats.cs
```namespace Treehouse.CodeChallenges
{
class FrogStats
{
public static double GetAverageTongueLength(Frog[] frogs)
{
double sum = 0.0;
for (int i = 0; i < frogs.Length; i++)
{
sum += frogs[i];

return sum / (frogs.Length);
}
}
}
}
```
Frog.cs
```namespace Treehouse.CodeChallenges
{
public class Frog
{
public int TongueLength { get; }

public Frog(int tongueLength)
{
TongueLength = tongueLength;
}
}
}
``` • frogs is an array of frogs. So frogs doesn't contain a number, it contains a frog What you actually want is the length of the frog's tongue at that index.
Hope this helps, but let me know if you need more assistance! 