Correct format specifier for double in printf - Stack Overflow
Format %lf in printf was not supported in old (pre-C99) versions of C language, which created superficial "inconsistency" between format specifiers for double in printf and scanf.

What is the difference between "Double" and "double" in Java?
39 This question already has answers here: Double vs double in java [duplicate] (7 answers) Difference between decimal, float and double in .NET? (19 answers)

c++ - double and accuracy - Stack Overflow
A double typically provides 16 (±1) decimal digits. Your example shows this: 4 8 12 16 v v v v 0.947368421052631578 long double 0.947368421052631526 double The answers agree to 16 digits. This is what should be expected. Also, note that there's no guarantee in the C Standard that a long double has more precision than a double. The last decimal digit (16th or 17th) is not necessarily accurate ...

decimal vs double! - Which one should I use and when?
When should I use double instead of decimal? has some similar and more in depth answers. Using double instead of decimal for monetary applications is a micro-optimization - that's the simplest way I look at it.

How do I print a double value with full precision using cout?
In my earlier question I was printing a double using cout that got rounded when I wasn't expecting it. How can I make cout print a double using full precision?

java - Cast Double to Integer - Stack Overflow
494 A Double is not an Integer, so the cast won't work. Note the difference between the Double class and the double primitive. Also note that a Double is a Number, so it has the method intValue, which you can use to get the value as a primitive int.

What does the !! (double exclamation mark) operator do in JavaScript ...
The double "not" in this case is quite simple. It is simply two not s back to back. The first one simply "inverts" the truthy or falsy value, resulting in an actual Boolean type, and then the second one "inverts" it back again to its original state, but now in an actual Boolean value. That way you have consistency:

c++ - what's a variable with & -> double& - Stack Overflow
5 double& is just a double passed by reference. In VB.NET, it would be declared ByRef dec_deg as Double. EDIT: However, I would recommend instead of using a void function to set a value by reference, just change the return type to double and return the expression instead of having to pass a variable by reference.

Should I use double or float? - Stack Overflow
A double has a much higher precision due to it's difference in size. If the numbers you are using will commonly exceed the value of a float, then use a double. Several other people have mentioned performance isssues. That would be exactly last on my list of considerations. Correctness should be your #1 consideration.

How to compare two double values in Java? - Stack Overflow
A simple comparison of two double values in Java creates some problems. Let's consider the following simple code snippet in Java. package doublecomparision; final public class DoubleComparision ...