Search Results

Search found 4493 results on 180 pages for 'operator keyword'.

Page 41/180 | < Previous Page | 37 38 39 40 41 42 43 44 45 46 47 48  | Next Page >

  • Bizzare Java invalid Assignment Operator Error

    - by Kay
    public class MaxHeap<T extends Comparable<T>> implements Heap<T>{ private T[] heap; private int lastIndex; private static final int defaultInitialCapacity = 25; public void add(T newItem) throws HeapException{ if (lastIndex < Max_Heap){ heap[lastIndex] = newItem; int place = lastIndex; int parent = (place – 1)/2; //ERROR HERE********** while ( (parent >=0) && (heap[place].compareTo(heap[parent])>0)){ T temp = heap[place]; heap[place] = heap[parent]; heap[parent] = temp; place = parent; parent = (place-1)/2; }else { throw new HeapException(“HeapException: Heap full”); } } } Eclipse complains that there is a: "Syntax error on token "Invalid Character", invalid AssignmentOperator" With the red line beneath the '(place-1)' There shouldn't be an error at all since it's just straight-forward arithmetic. Or is it not that simple?

    Read the article

  • Volatile keyword

    - by Tiyoal
    Say I have two threads and an object. One thread assigns the object: public void assign(MyObject o) { myObject = o; } Another thread uses the object: public void use() { myObject.use(); } Does the variable myObject have to be declared as volatile? I am trying to understand when to use volatile and when not, and this is puzzling me. Is it possible that the second thread keeps a reference to an old object in its local memory cache? If not, why not? Thanks a lot.

    Read the article

  • the use of private keyword

    - by LAT
    Hi everyone I am new to programming. I am learning Java now, there is something I am not really sure, that the use of private. Why programmer set the variable as private then write , getter and setter to access it. Why not put everything in public since we use it anyway. public class BadOO { public int size; public int weight; ... } public class ExploitBadOO { public static void main (String [] args) { BadOO b = new BadOO(); b.size = -5; // Legal but bad!! } } I found some code like this, and i saw the comment legal but bad. I don't understand why, please explain me.

    Read the article

  • Performing multiple operations if condition is satisfied in ternary operator in linq

    - by user1575914
    I am a beginner in LINQ.I want to perform some conditional operation lik follows, (from emp in Employees let DOB=emp.BirthDate.GetValueOrDefault() let year=DOB.Year let month=DOB.Month let EmpAgeInYearsToday=DateTime.Now.Year-year let EmpAgeInMonthToday=DateTime.Now.Month-month let temp_year=(EmpAgeInYearsToday-1) let ExactNoOfMonths_temp=EmpAgeInMonthToday<0?temp_year:EmpAgeInMonthToday let ExactNoOfMonths=EmpAgeInMonthToday<0?EmpAgeInMonthToday+12&temp_year:EmpAgeInMonthToday select new{emp.EmployeeID,DOB, EmployeeAgeToday=EmpAgeInYearsToday+" Years "+ExactNoOfMonths+" Months ").Dump(); Here, let ExactNoOfMonths=EmpAgeInMonthToday<0?EmpAgeInMonthToday+12&temp_year:EmpAgeInMonthToday This part is not working. How to achieve this? How to perform multiple operations when the condition is satisfied?

    Read the article

  • const keyword in Objective-c

    - by user392412
    int main(int argc, char *argv[]) { @autoreleasepool { const int x = 1; const NSMutableArray *array1 = [NSMutableArray array]; const NSMutableString *str1 = @"1"; NSString * const str2 = @"2"; // x = 2; compile error [array1 addObject:@"2"]; // ok // [str1 appendString:@"2"]; // runtime error // Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Attempt to mutate immutable object with appendString:' // str2 = @"3"; compile error } } my Question is Why array1 addObject is legal and why str1 appendString is forbidden?

    Read the article

  • INSERT INTO ...SELECT syntax error in join operator

    - by user1477356
    I'm trying to write a shopping basket into a order + orderline in a sql database from C# asp.net. the orderline will contain a ordernumber, total price, productid, quantity etc. for every item in the basket. The order itself will contain the ordernumber as primary key and will be linked to the different lines through it. Everything worked fine yesterday, but now as i tried to use a SELECT command in the insert into statement to get things more dynamic i'm getting the above described syntax error. Does anybody know what's wrong with this statement: INSERT INTO [order] (klant_id,totaalprijs,btw,subtotaal,verzendkosten) SELECT klant.id , SUM(orderregel.totaalprijs) , SUM(orderregel.btw) , SUM(orderregel.totaalprijs) - SUM(orderregel.btw) , 7.50 FROM orderregel INNER JOIN klant ON [order].klant_id = klant.id WHERE klant.username = 'jerry' GROUP BY id; the ordernumber in the "order" table is on autonumber, in the asp codebehind there is a for each which handles the lines being written for every product, there's an index set on 0 outside of this loop and is heightened with 1 every end of it. The executenonquery of the order is only executed once at the beginning of the first loop and the lines are added after with MAX(ordernumber) as ordernumber. I hope i have provided enough information and somebody is capable of helping me. Thanks in advance!

    Read the article

  • Assignment in conditional operator

    - by DuoSRX
    I've seen a lot this kind of code recently : if ($foo = $bar->getFoo()) { baz($foo); } Is this considered good or bad practice ? For example, Netbeans IDE give a notice if you use this kind of code : Possible accidental assignment, assignments in conditions should be avoided What do you think ?

    Read the article

  • Factory Method Using Is/As Operator

    - by Swim
    I have factory that looks something like the following snippet. Foo is a wrapper class for Bar and in most cases (but not all), there is a 1:1 mapping. As a rule, Bar cannot know anything about Foo, yet Foo takes an instance of Bar. Is there a better/cleaner approach to doing this? public Foo Make( Bar obj ) { if( obj is Bar1 ) return new Foo1( obj as Bar1 ); if( obj is Bar2 ) return new Foo2( obj as Bar2 ); if( obj is Bar3 ) return new Foo3( obj as Bar3 ); if( obj is Bar4 ) return new Foo3( obj as Bar4 ); // same wrapper as Bar3 throw new ArgumentException(); } At first glance, this question might look like a duplicate (maybe it is), but I haven't seen one exactly like it. Here is one that is close, but not quite: http://stackoverflow.com/questions/242097/factory-based-on-typeof-or-is-a

    Read the article

  • C++ operator[ ] on integer litteral

    - by gregseth
    I found this piece of code: char a = 1["ABC"]; A few quick test led me to the fact it was the same than writing: char a = "ABC"[1]; Which seems far more logical to me. So my questions: Why is this notation valid? Is there any reason to write something that way?

    Read the article

  • Operator & and * at function prototype in class

    - by Puyover
    I'm having a problem with a class like this: class Sprite { ... bool checkCollision(Sprite &spr); ... }; So, if I have that class, I can do this: ball.checkCollision(bar1); But if I change the class to this: class Sprite { ... bool checkCollision(Sprite* spr); ... }; I have to do this: ball.checkCollision(&bar1); So, what's the difference?? It's better a way instead other? Thank you.

    Read the article

  • Is tertiary operator possible here?

    - by silow
    I'm trying to set $value1, $value2, $value3 entirely using tertiary operators. This is what it looks like without tertiary if ($chk1 == 20) { $value1 = true; if ($chk2 == 40) { $value2 = 100 ; $value3 = 300; } else { $value2 = 200 ; $value3 = 400; } } else { $value1 = false; } I can set $value2 and $value3, but not sure how to set $value1. Can it be done? if ($chk1 == 20) { $value1 = true; $value2 = ($chk2 == 40) ? 100 : 200; $value3 = ($chk2 == 40) ? 300 : 400; } else { $value1 = false; }

    Read the article

  • Java print binary number using bit-wise operator

    - by user69514
    Hi I am creating a method that will take a number and print it along with its binary representation. The problems is that my method prints all 0's for any positive number, and all 1's for any negative number private static void display( int number ){ System.out.print(number + "\t"); int mask = 1 << 31; for(int i=1; i<=32; i++) { if( (mask & number) != 0 ) System.out.print(1); else System.out.print(0); if( (i % 4) == 0 ) System.out.print(" "); } }

    Read the article

  • Perl need the right grep operator to match value of variable

    - by iaintunderstand
    I want to see if I have repeated items in my array, there are over 16.000 so will automate it There may be other ways but I started with this and, well, would like to finish it unless there is a straightforward command. What I am doing is shifting and pushing from one array into another and this way, check the destination array to see if it is "in array" (like there is such a command in PHP). So, I got this sub routine and it works with literals, but it doesn't with variables. It is because of the 'eq' or whatever I should need. The 'sourcefile' will contain one or more of the words of the destination array. my @destination = ('hi', 'bye'); sub in_array { my ($destination,$search_for) = @_; return grep {$search_for eq $_} @$destination; } for($i = 0; $i <=100; $i ++) { $elemento = shift @sourcefile; if(in_array(\@destination, $elemento)) { print "it is"; } else { print "it aint there"; } } Well, if instead of including the $elemento in there I put a 'hi' it does work and also I have printed the value of $elemento which is also 'hi', but when I put the variable, it does not work, and that is because of the 'eq', but I don't know what else to put. If I put == it complains that 'hi' is not a numeric value.

    Read the article

  • Ternary operator or chosing from two arrays with the boolean as index

    - by ajax333221
    Which of these lines is more understandable, faster jsPerf, easier to maintain?: arr = bol ? [[-2,1],[-1,2]] : [[-1,0],[-1,1]]; //or arr = [[[-1,0],[-1,1]], [[-2,1],[-1,2]]][bol*1]; I usually write code for computers (not for humans), but this is starting to be a problem when I am not the only one maintaining the code and work for a team. I am unsure, the first example looks neat but are two different arrays, and the second is a single array and seem to transmit what is being done easier. I also considered using an if-else, but I don't like the idea of writing two arr = .... Or are there better options? I need serious guidance, I have never worried about others seeing my code.

    Read the article

  • Is there a %in% operator accros multiple columns

    - by RobinLovelace
    Imagine you have two data frames df1 <- data.frame(V1 = c(1, 2, 3), v2 = c("a", "b", "c")) df2 <- data.frame(V1 = c(1, 2, 2), v2 = c("b", "b", "c")) Here's what they look like, side by side: > cbind(df1, df2) V1 v2 V1 v2 1 1 a 1 b 2 2 b 2 b 3 3 c 2 c You want to know which observations are duplicates, across all variables. This can be done by pasting the cols together and then using %in%: df1Vec <- apply(df1, 1, paste, collapse= "") df2Vec <- apply(df2, 1, paste, collapse= "") df2Vec %in% df1Vec [1] FALSE TRUE FALSE The second observation is thus the only one in df2 and also in df1. Is there no faster way of generating this output - something like %IN%, which is %in% across multiple variables, or should we just be content with the apply(paste) solution?

    Read the article

  • Multiple uses of "this" keyword in Java

    - by frodosamoa
    So, I have this. It compares two card decks and if they are the same the result is true. public boolean equals ( Object obj ) { boolean result = true; for (int i = 0; i < 52; i++) { if (this.cardAt(i) = this2.cardlist(i)) { result = true; } else { result = false; } } } I would like to be able to compare two random card decks, if you will. But I don't know how to compare two different ones using "this . I simply wrote "this2" to replace another instance of "this". What could I do to replace this "this2" to still be able to compare two card decks?

    Read the article

< Previous Page | 37 38 39 40 41 42 43 44 45 46 47 48  | Next Page >