equals

问题 Just tried to test speed of equals when using Objects.equals vs Primitive comparison. If somebody needs the code: import org.junit.Test; import org.openjdk.jmh.annotations.*; import org.openjdk.jmh.runner.Runner; import org.openjdk.jmh.runner.RunnerException; import org.openjdk.jmh.runner.options.Options; import org.openjdk.jmh.runner.options.OptionsBuilder; import org.openjdk.jmh.runner.options.TimeValue; import java.util.Objects; import java.util.concurrent.TimeUnit; class BaseEquals { byte

问题 I found the following jQuery, and it works great for a page that does not have dynamic content in a grid loading on the page as you click from tab to tab. One tabbed section of the grid, the default, will adjust the equal height correctly with the below jQuery, but when the user then clicks on one of the other tabs to load other content into the grid (in which the grid is a lot more content), the equal height jQuery does not adjust, which results in the content in the grid explaning beyond

问题 I came across one programming issue that I have tried to solve it as follows: dsDataSet.Tables("promotion") = New DataTable. But Unfortunately this does not work because error: property 'Item' is read only Is there away to accomplish this? 回答1: The Tables collection of a DataSet could be modified using the Add, Remove methods dsDataSet.Tables.Add(new DataTable("promotion")) of course, the line above requires that the collection doesnt already contain a table named "promotion". If you have

问题 I'll try to explain my problem as clear as possible :). I am using PropertyChangeSupport to notify registered views for changes in the properties. One of the property is an object which properties are changed every view seconds. I don't want to create for this particular object new instance every time it is being updated (for the propertychangelistener to notice the change), so I wrote my own equals method where I ommit the comparation to itself. @Override public boolean equals(Object item) {

问题 #include<iostream> #include<vector> std::vector<std::string> vector1; int main() { vector1.push_back("adadad"); std::vector<std::string> vector2; vector2.push_back("adadd"); if (vector1==vector2) { std::cout<<"success"; } else { vector1.swap(vector2); vector2.clear(); vector2.push_back("adadd"); if (vector1==vector2) { std::cout<<"success_swap"; } } } Now this works in g++ but not in visual studio. The operator == doesn't work here and throws compilation error in visual studio 2010(ultimate).

问题 The same goes for '1\t' (and probably others). if (1 == '1\n') { console.log('Equal'); } else { console.log('Not Equal'); } 回答1: As said before if you compare number == string , it will automatically try to convert the string to a number. the \n and \t are simply whitespace characters and therefore ignored. This and similar behaviour can be rather confusing leading to situations like this: (Picture taken from: https://www.reddit.com/r/ProgrammerHumor/comments/3imr8q/javascript/) 回答2: The

问题 This question already has answers here : What is the best algorithm for overriding GetHashCode? (19 answers) Closed 4 years ago . I have a struct that overrides the Equals() method and the compiler complains about GetHashCode() not being overridden. My struct: private struct Key { ... public override int GetHashCode() { return ?; } public int FolderID; public MyEnum SubItemKind; public int SubItemID; } What is the right way to implement the GetHashCode() method? a) return FolderID ^

问题 class Hash { int a; Hash(int h){ a=h; } public boolean equals(Object o) { Boolean h=super.equals(o); System.out.println("Inside equals "); return h; } public int hashCode() { System.out.println("Inside Hash"); return 2; } } public class Eq { public static void main(String...r) { HashMap<Hash,Integer> map=new HashMap<Hash,Integer>(); Hash j=new Hash(2); map.put(j,1); map.put(j,2); System.out.println(map.size()); } } output was inside hash inside hash 1 Since it returns the same hashcode , the

问题 I am just wondering what the process is for checking the object type of something. Basically I have an array of parent objects and I want to check if one of those objects is of a particular child type. more specifically, I want to check if an array of GameScreen objects contains a GameScreen object of type GameplayScreen. GameScreen[] screens = mScreenManager.GetScreens(); // loop through array and check if the object equals gameplayscreen } 回答1: You can check the type using is operator like:

问题 I have a class Person for which I have to override the Equals and GetHashCode method. Two person objects are equals if the Name matches OR if the Email matches. What's a good way of doing this with a considerably efficient hash function? class Person { string Name string Email public override Equals(object obj) { if (ReferenceEquals(obj, null)) return false; if (ReferenceEquals(this, obj)) return true; if (obj is Person) { Person person = (Person)obj; return (this.Name == person.Name) ||