Question

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Direct casting vs 'as' operator?

Can someone explain the difference to me and which one is better to use? I know in some situations I can only use one or the other.

(int)value

value as int

Answer 1

The latter is invalid. You can use

value as int?

if you need to “convert if possible”. That’s slower than

if (value is int)
{
    int x = (int) value;
    ...
}

though. That’s what you should probably use if you’re not confident that value is actually an int. If, however, your code is such that if value isn’t an int, that represents a bug, then just cast unconditionally:

int x = (int) value;

If that fails, it will throw an exception – which is generally appropriate for a bug.