Encoding numbers

Question

I am a developer using high level languages. I usually take the lower level details for granted.

I read that standards such as ASCII and Unicode are for character encodings. A character has to be stored as a number. Is this the same for numbers? For example, if I declare a variable in .NET like this:

dim test as integer=5

In this case the value of test (5) will be represented as decimal: 49 according to this table . Is that correct?

Answer 1

If you code Dim test As String = "5" the value will be stored using the Unicode encoding for the character "5". However, Integers (and other numeric types) are not strings and are not encoded in that way, they are represented internally using their numeric value. An Integer is stored as a 32 bit value.

Answer 2

what you are asking about is data representation in memory.The way integers are represented depends on the whether they are signed or unsigned. IF they are signed (usually the case, unless you specify type as unsigned int or something equvalent) they are represented in binary in two's complement form: http://en.wikipedia.org/wiki/Two%27s_complement