Why is it preferred to use Lists instead of Arrays in Java?

Many people and authors suggested to us to use list than array. List <Integer> list = new ArrayList<Integer>(); list.addElement(1); …. What it is the reason behind it? Answer You should generally prefer to choose the right data structure for the job. You need to understand your task at hand as well as all the different … Read more

List of all domain classes in Grails

how can I get a list of alle domain classes I use in my project? Something like GORM.domains.list(). Answer Using grailsApplication.getArtefacts(“Domain”) you get a list of GrailsDomainClass instances that hold meta-information regarding the domain class. The domain class itself is returned by Calling getClazz(). In short: grailsApplication.getArtefacts(“Domain”)*.clazz returns a complete list of the existing domain … Read more

Find if an element with a specific property value is found in a list

I’m trying to find a value in a list of objects in kotlin, using for it “filter”, but I need to return true or false if the value is found, but filter returns me a list of object in the case of match. t.filter { it.retailerId == value } ¿How I can return a boolean … Read more

Can I use an object (an instance of a class) as a dictionary key in Python?

I want to use a class instance as a dictionary key, like: classinstance = class() dictionary[classinstance] = ‘hello world’ Python seems to be not able to handle classes as dictionary key, or am I wrong? In addition, I could use a Tuple-list like [(classinstance, helloworld),…] instead of a dictionary, but that looks very unprofessional. Do … Read more

How to Search a String in List> in C#

I am having a List<Tuple<string,string>> tr = new List<Tuple<string,string>>(); tr.Add(new Tuple<string, string>(“Test”,”Add”); tr.Add(new Tuple<string, string>(“Welcome”,”Update”); foreach (var lst in tr) { if(lst.Contains(“Test”)) MessageBox.Show(“Value Avail”); } I failed while doing this ,…. Answer If you’d like to use LINQ: if(tr.Any(t => t.Item1 == “Test” || t.Item2 == “Test”)) MessageBox.Show(“Value Avail”); This will also have the benefit … Read more

Scala – Combine two lists in an alternating fashion

How do I merge 2 lists in such a way that the resulting list contains the elements of 2 lists in alternating fashion in Scala. Input: val list1 = List(“Mary”, “a”, “lamb”) val list2 = List(“had”, “little”) Output: List(“Mary”, “had”, “a”, “little”, “lamb”) Answer What you’re looking for is usually called “intersperse” or “intercalate” and … Read more