comparison

问题 I have an Array of MKAnnotation objects called arrAnnotations . I want to pick out one of the annotations with the same coordinate as the one stored in a CLLocation object called "newLocation". I'm trying to use a NSPredicate , but it doesn't work. NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(SELF.coordinate == %f)", newLocation.coordinate]; NSArray* filteredArray = [arrAnnotations filteredArrayUsingPredicate:predicate]; [self.mapView selectAnnotation:[filteredArray

问题 According to an article Groovy has Unfortunately at the same time Groovy is very slow at runtime. As a person, who did a lot to improve performance of Groovy I can probably speak about that very openly. Groovy is very slow. You can easily expect that some Groovy calculation or data transformation rewritten in Java will become 3-5 times faster. Usually this factor is 8-12 and sometimes even higher. Someone can say that Java is always at our service and nobody uses Groovy for calculations or

问题 For example; we have three variables: var a = 11; var b = 23; var c = 8; Can we return the variable name of the biggest/smallest value? 回答1: you probably need to use an object or an array to know the variable's name : var obj = { 'a':11, 'b':23, 'c':8 }; var biggest = ''; for (var name in obj) { if(biggest !== '' && obj[name] > obj[biggest]) { biggest = name; } else if (biggest === '') { biggest = name; } } return biggest; 回答2: Math.max(a, b, c) If you have variable number of items in an

问题 Good morning, i have checked many responses about this topic, but without success...very sorry... i have got an xml document with an element 'courses' ("seances") which has 'course' éléments ("seance") : (i have deleted unnecessary details) .... <seances> <seance date="2014-09-10T00:00:01"> ...details in a 'seance' </seance> <seance date="2013-09-10T00:00:01"> ... </seance> ...other 'seance' elements </seances> and my xslt stylesheet produces an html document : <xsl:stylesheet xmlns:xsl="http

问题 var = 86 print((var < 90) & (var >= 80)) prints True . But why do all these print False ? print(var < 90 & var >= 80) print(var < 90 & (var >= 80)) print((var < 90) & var >= 80) print(var < 90 & True) 回答1: You should be using the and operator instead for boolean operations. Since python supports chaining relational operators (i.e. you can use 0 < var < 100 instead of 0 < var and var < 100 ) and processes binary operations (i.e. addition, subtraction, bitwise operations, etc.) before

问题 I am developing Alarm Clock. I want to compare a time now and setTime. Is it possible to compare in minutes only. My Problem is NSDate will compare in seconds, for example 9:38:50 is not equal to 9:38:00. how can I compare in minutes? 回答1: First, convert them to UNIX timestamp ignoring milliseconds. NSUInteger time1 = (NSUInteger)[date1 timeIntervalSince1970]; NSUInteger time2 = (NSUInteger)[date2 timeIntervalSince1970]; Ignore seconds. time1 = time1 - (time1 % 60); time2 = time2 - (time2 %

问题 I am trying to compare two set of column ranges in Excel. i am aware of the standard comparison formula : Eg. =(A1=E1) What I am looking for is a replacement for the following formula =AND(A1=E1,B1=F1,C1=G1) since the number of columns is large I was thinking if it is possible to use a cell range. 回答1: A bit slower than @Chronocidal, just to observe that =AND(A1:C1=E1:G1) also works if entered as an array formula using Ctrl Shift Enter 回答2: =SUMPRODUCT(PRODUCT(--(A1:D1=E1:H1))) The SUMPRODUCT

问题 In DOS/Batch, if 08 lss 1 echo true echoes "true". The same applies to 09. Both 08 and 09 are less than 1. However, if 07 lss 1 echo true does not echo anything. 01 to 07 are not less than 1. Why? What is special about 08 and 09? 回答1: Typically, a leading 0 indicates you'd like the number to be parsed in octal. I'd expect 08 or 09 to actually be an error condition ; perhaps the batch language does not have a good mechanism to signify that the input was incorrect? 回答2: Extending the answers

问题 I know it has been asked and answered millions of times but still I am unable to figure out why I am receiving with the violation during sort. Here is my code: Collections.sort(sorted, new Comparator<MyObject>() { @Override public int compare(MyObject m1, MyObject m2) { // Actual energy comparison :- // THE higher the energy, the earlier in the list float delta = m1.getTotalEnergy() - m2.getTotalEnergy(); if (delta > 0) { return 1; } else if (delta < 0) { return -1; } else { return 0; } } });

问题 I have a Comparator<Foo> with the following comparison function: float d = o1.bar - o2.bar; if (Math.abs(d) <= 0.001) { return 0; } else { return d < 0 ? -1 : 1; // inline Math.copySign } Essentially, this is supposed to compare two Foo s based on their bar property unless the values are close enough, in which case they should be declared equal. (This is important because I'm doing another sort after this, on a different property.) Obviously, though, this is not a transitive comparator. If