java

[Solved] Run as java application not working

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You absolutely need a main method to run this class, consider there is no instance of this class created in a different class (even then, it would have to have a main method). EDIT: I guess if your goal is to run the addNotificationMessage1() method, you could create the following main method: public static void … Read more

[Solved] Java Array.sort algo explanation [closed]

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The sorting algorithm for Arrays.sort(int[] a) is a tuned quicksort. Ref: https://docs.oracle.com/javase/6/docs/api/java/util/Arrays.html#sort(int[]) Read this article: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.14.8162&rep=rep1&type=pdf for understanding the Quick-sort used in Array.sort() by JON L. BENTLEY & M. DOUGLAS McILROY In Java 7 pivot dual quick-sort algorithm is used for Arrays.sort(int[] a) i.e. refer this: What’s the difference of dual pivot quick sort and … Read more

[Solved] Need to calculate the average from a loop java

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You can simplify die1 = (Math.random()*6)+1; die1 = (int) die1; To die1 = (int) ((Math.random() * 6) + 1); But you don’t need to cast it to an integer if you want exact values, thats going to truncate (get rid of) your decimal places. To sum all rolls, int total = 0; int maxRolls = … Read more

[Solved] Compare two files in Java [closed]

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Use fileInputStream then use two nested for loop O(n^2) i know, just for now. then use .hasNext() <– boolean for your stream object and if true use .next() which checks line by line solved Compare two files in Java [closed]

[Solved] How to make a 2d array in JAVA?

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If you could please point me towards some reading material that can teach me how to add, remove, get and iterate over the elements of the method suggested by you. Arrays don’t support those operations. To add and remove elements you really need to use a List such as ArrayList. List<List<Integer>> list2d = new ArrayList<>(); … Read more

[Solved] Why this code is not printing 30, since int is primitive and mutable?

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Why this code is not printing 30 Because you’re outputting the age field of person2, which you never set to 30. You’re setting the age field of person1 to 30, but not person2. Instance fields are instance-specific. In particular, if you were expecting this line to create some link between the instances: person2.setAge(person1.getAge()); it doesn’t. … Read more

[Solved] My app resets data when it is minimized

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onStart is called every time the app starts. onCreate on the other hand, is only called when the app starts or after the activity process has been killed and restarted. Usually the last scenario means after onStop is called and the activity process is killed, but it isn’t destroyed yet. Move that code to onCreate, … Read more

[Solved] Pasing a line and getting values [closed]

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I’m assuming the input is Java. To simply extract the values, you can do String str = “rtt min/avg/max/mdev = 10.876/13.344/17.155/2.736 ms”; String[] strings = str.split(” “); // split string on spaces, 5 new strings str = strings[3]; // select the 4th of these strings strings = str.split(“https://stackoverflow.com/”); // split again, this time on “https://stackoverflow.com/” … Read more

[Solved] problems with adding action button in android tutorial

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I had the following error: The styles.xml at v14 looked the following <!– Base application theme for API 14+. This theme completely replaces AppBaseTheme from BOTH res/values/styles.xml and res/values-v11/styles.xml on API 14+ devices. –> <style name=”AppBaseTheme” parent=”Theme.AppCompat.Light.DarkActionBar”> <!– API 14 theme customizations can go here. –> </style> The search button was not visible because the … Read more