notation

I am assigned some old code and when I was reading through it, I noticed it had these in the form of: float low = 1e-9; float high = 1e9; float lowB = 1e-9; float highB = 1e9; float lowL = 1e-9; float highL = 1e9; So I see that it's trying to define some ranges using the e notation, right? But isn't 1e-9 supposed to be -1e9 ? Then the values would be between -1000000000 and 1000000000 , right? I am not sure what 1e-9 is meant for? Neither is more correct than the other. They just represent different values. 1e-9 is 0.000000001 ; the minus sign applies to the exponent. -1e9 is -1000000000.0 ;

I'm not sure if this is a proper programming question, but it's something that has always bothered me, and I wonder if I'm the only one. When initially learning C++, I understood the concept of references, but pointers had me confused. Why, you ask? Because of how you declare a pointer. Consider the following: void foo(int* bar) { } int main() { int x = 5; int* y = NULL; y = &x; *y = 15; foo(y); } The function foo(int*) takes an int pointer as parameter. Since I've declared y as int pointer, I can pass y to foo , but when first learning C++ I associated the * symbol with dereferencing, as such

So I'm trying to document the format of the json returned by an api I am writing against and I'd like to know if there is any popular format for the documentation of json structure. Note I'm not trying to to test or validate anything, I'm just using this for documentation. Also some ways to add comments to non-constants(items always returned w/ the same value) would be nice. This the not totally thought out scheme I'm currently using: Plain names refer to identifiers or types. Some types have type-comment Strings that appear to be constant(always returned for that type of request) strings are

Example 1: var ca = p.GetCustomAttribute<ConnectorAttribute>(); return ca?.Point.IsEqual(cp) ?? false; Example 2: var ca = p.GetCustomAttribute<ConnectorAttribute>(); return (null != ca) && ca.Point.IsEqual(cp); Question: Does the two example return the same result? Which one performs better? Are there any concerns about thread safety? Edit: Nobody mention but the title had some error, I've corrected it. Edit 2: According the comments, 'those code are the same'. For me it is still not as trivial as it seams to be. The answer here tells that the first part of example 1. creates a Nullable<bool>

Let's say I have two floats a <- 8.9384920e-24 b <- 0.00293892837 I would like to display either of them in 10-base scientific notation rounded to two decimals on a graph, possibly using paste() , but with superscript formatting after the 10. 8.94 x 10^-24 #no ^ and superscript font 2.94 x 10^-4 #no ^ and supercript font, should be -4, not -04 This is really maniac but it has been requested by a superior, it has to be done in base R (not ggplot2) or I will have to re-write 600 lines of code... Right now all I can see is that floats are printed differently depending on how big they are... You

I know this is a total newbie question, but the answer may not be obvious to many new programmers. It wasn't initially obvious to me so I scoured the Internet looking for Perl modules to do this simple task. Kurt W. Leucht sprintf does the trick use strict; use warnings; my $decimal_notation = 10 / 3; my $scientific_notation = sprintf("%e", $decimal_notation); print "Decimal ($decimal_notation) to scientific ($scientific_notation)\n\n"; $scientific_notation = "1.23456789e+001"; $decimal_notation = sprintf("%.10g", $scientific_notation); print "Scientific ($scientific_notation) to decimal (