Left bit shifting 255 (as a byte)

Question

Can anyone explain why the following doesn't compile? ``` byte b = 255 << 1 ``` The error: Constant value '510' cannot be converted to a 'byte' I'm expecting the following in binary: ``` 1111 1110 ``` The type conversion has stumped me.

Accepted Answer

Numeric literals in C# are `int`, not `byte` (and the bit shift will be evaluated by the compiler, hence only the 510 remains). You are therefore trying to assign a value to a `byte` which does not fit. You can mask with 255:

```
byte b = (255 << 1) & 0xFF
```

to reduce the result to 8 bits again. Unlike Java, C# does not allow overflows to go by undetected. Basically you'd have two sensible options when trying to assign 510 to a byte: Either clamp at the maximum value, then you'd get 255, or throw away the bits that do not fit, in which case you'd get 254.

You can also use `unchecked`, as lassevk mentioned:

```
byte b = unchecked((byte)(255 << 1));
```

Left bit shifting 255 (as a byte)

Solution

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