C# Float vs. VB.net Single - Namin' complainin'

Question

Why is it called a single in VB.net? I'm sure there is a good reason but it doesn't seem intuitive to a non formally trained programmer like me.

score 35 · Accepted Answer · answered Nov 07 '08 at 13:38

35

BPAndrew's question seems to be really "why float in C# and Single in VB.NET", which noone actually answered, so here's my 2p...

The use of "float" in C# seems to be a throwback to its C/C++ heritage. "float" still maps to the System.Single type in C#, so the keyword just exists for convenience. You could just as well declare the variable as "Single" in C# the same as you do in VB.NET.

(And as stated above, naming them Single/Double actually makes more sense as they are single/double precision floating-point numbers.)

answered Nov 07 '08 at 13:38

Xiaofu

15,523
2
32
45

2p, that's pretty costly, compared to the CDN penny. – LeppyR64 Nov 07 '08 at 14:08
1

`double` is another keyword in C# that exits for convenience that maps to `System.Double`. – JohnB Jul 28 '10 at 14:49

score 19 · Answer 2 · answered Nov 07 '08 at 14:18

19

As others have said, they map to "single" and "double" precision binary floating point types. Personally I think it was a sideways step to just name System.Single and System.Double - why not System.Float32 and System.Float64 to match the integer types?

answered Nov 07 '08 at 14:18

Jon Skeet

1,421,763
867
9,128
9,194

2

Also, the [CIL](http://en.wikipedia.org/wiki/Common_Intermediate_Language) calls them `float32` and `float64`, respectively, corresponding exactly to the `System.Single` and `System.Double` of the [BCL](http://en.wikipedia.org/wiki/Base_Class_Library). – Jeppe Stig Nielsen Jan 22 '15 at 15:43

score 8 · Answer 3 · answered Nov 07 '08 at 13:12

The reason is that both single and double are both Floating Point numbers.

single is short for Single Precision Floating Point Number (32 bits)
double is short for Double Precision Floating Point Number (64 bits)

Therefore to call a floating point number float is ambiguous.

http://en.wikipedia.org/wiki/Single_precision
http://en.wikipedia.org/wiki/Double_precision

score 2 · Answer 4 · edited Nov 04 '19 at 17:05

2

I think it is a shorthand for "Single-precision" Double is "Double-precision"

While C-style int and float was probably referring to "integer" and "floating point"

edited Nov 04 '19 at 17:05

ArunPratap

4,816
7
25
43

answered Nov 07 '08 at 13:08

chakrit

61,017
25
133
162

int means integer, which is wholly different than a fixed-point (decimal) number. fixed-point is exactly that, a real number with a pre-set (fixed) precision. http://mathforum.org/dr.math/faq/faq.integers.html – Robert Paulson Nov 07 '08 at 23:07

score 1 · Answer 5 · answered Nov 04 '11 at 13:53

I would like to add my hypothesis for the naming convention.

In the C/C++ word that Java and then C# were born out of, int/long and float/double could vary based on the architecture in which it resides, 32-bit or 64-bit.

In portable VM languages like Java and C#, these types do NOT change, and therefore, the naming convention could reflect that. Or it could just be what's most comfortable the last generation of programmers. Or we could create aliases for everything and let everyone do whatever they want!!

score 0 · Answer 6 · answered Nov 07 '08 at 13:11

0

The technical name is a 'single precision floating point', 'single' because it takes a single word in memory (32 bits). A double, meanwhile, takes 64 bits on most architectures.

answered Nov 07 '08 at 13:11

C. Broadbent

753
4
11

1

Originally the single didn't mean single word, since they were 16 bit machines. Floating point and its precision has been around longer than 32 bit machines have. – kenny Nov 07 '08 at 13:13

C# Float vs. VB.net Single - Namin' complainin'

6 Answers6

Linked