double

问题 This question already has answers here : What is the difference between float and double? (11 answers) Floating point comparison [duplicate] (5 answers) Closed 6 years ago . I am running this program. But getting strange result. int main() { float a=.8; if(a < .8) printf("a is small\n"); else printf("a is not small\n"); float b=.7; if(b < .7) printf("b is small\n"); else printf("b is not small\n"); return 0; } It gives me output-- a is not small b is small 回答1: Why don't you use 0.7f . 0.7 Is

问题 This question already has answers here : Why is 128==128 false but 127==127 is true when comparing Integer wrappers in Java? (6 answers) How to properly compare two Integers in Java? (10 answers) Closed 10 months ago . My Question about Wrapper classes. Case 1: I'm Declaring two Integer variables and assigning same values 127 , and i'm printing both hashCode. It's Generated same hashCode and result will be printed true . But In Case 2: Generated the Same hashCode but result will be printing

问题 Closed . This question needs details or clarity. It is not currently accepting answers. Want to improve this question? Add details and clarify the problem by editing this post. Closed 6 years ago . I'm reading the following code(in ch. 5, inheritance, of Horstman's Core Java): double dx = (to - from) / (n-1); for (double x = from; x <= to; x += dx) { double y = (Double) f.invoke(null, x); System.out.printf(%10.4f | %10.4f%n" + y, x, y); } Why would you use double variables at all in a for

问题 My function below will occasionally produce an infinite number. I had thought that I could use my rounding function below to avoid using the infinite number...in other words 1.333333333333(INF) rounded to 1.33, however the compiler still treats the result of the INF.rounded as infinite, how can I round so that I can still put out a value here? Speficially I'm trying to encode to JSON and getting this error: metadata ERROR = invalidValue(inf, Swift.EncodingError.Context(codingPath: [Watch

问题 I'm new in regex .. How can I parse the string through regex Balance 123,45 p. to double 123.45 回答1: You can use String.split() with space as a delimilter and than use String.replaceAll() to replace , with . . After that use parseDouble.It returns, Returns a new double initialized to the value represented by the specified String, as performed by the valueOf method of class Double. String number = "Balance 123,45 p."; String[] number_array = number.split(" "); String str = (number_array[1]

问题 I've read a few other answers on different posts about people having specific problems with line formatting, but have not found anything that has helped enough to solve my problem. I've also looked at the java docs and nothing I have done seems to work. The last line of code is the one I'm trying to format. I ideally want to format it with 3 decimal precision output. Double hi = 32.22; System.out.println("The sqrt. is = " + Math.sqrt(hi)); System.out.printf("The Sqrt Rounded Down Is: " + "/%

问题 Ive created a program to compute the value of an integral from zero to infinity, however when i go to print my answer it only prints it to 6 decimal places, could someone advise on why this is? Thanks very much in advance :) #include <stdio.h> #include <math.h> #include <float.h> double integral_Function(double x){ double value; value = 1/((1+ pow(x, 2))*(pow(x, 2/3))); return value; } double trapezium_Rule(double lower, double upper, int n){ double h; double total; h = (upper - lower)/n;

问题 Important Edit: The original question was about getting the density of both doubles and fractions. As i get the answer for doubles and not for fractions, I'm changing the topic to close this question. The other half of the original question is here New question I want to find the density of doubles between 2 given numbers but I can't think of a good way. So I'm looking for a closed-form expressions doublesIn(a,b). Or some code that does the work in a reasonable time. With doubles i should use

问题 I have a SQL query which return records with only one column of type decimal (18,18). In the C++ code I need to convert each value to double to add it to an array. What's the best way of doing it? Thank you 回答1: I would suggest converting it to a Real before taking it from the database they are roughly the same datatype. http://msdn.microsoft.com/en-us/library/ms173773.aspx 来源： https://stackoverflow.com/questions/6746010/convert-decimal-sql-to-double-c

问题 I was performing addition and subtraction on an input of decimals that are precise to the second decimal place. I tried to improve accuracy by converting them to integers through multiplying 100, but achieved opposite effects. Consider the following code and output: double d = 2.01; int a = (int) (d * 100.0); cout << a << endl; The output is: 200 Once and for all, what are some of the best practices regarding floating-point arithmetics? Is it at all feasible to first convert the double to an