You aren’t, according to the code, acessing(opening) the database. You are just instantiating the DatabseHelper in MainActivity i.e. mydb = new CrdDBHelper(this); It is not until an attempt is made to open the database (which is frequently implicit) that the database is actually created. A simple way would be to force an open when instantiating … Read more
Whenever you need to run anything ,you always need a starting point, So Java language developers decided to have this main Method as starting point of execution. and So your code does not compile ,because these statements cannot be directly in class. Only variable declarations are allowed directly inside class,everything else needs to go inside … Read more
public class Program { public static void main(String[] args){ int[] numbers = new int[10]; for (int i = 0; i < 10; i++) { numbers[i]=i+1; } for (int i : numbers) { System.out.println(i); } } } solved Count from 1-10 using a loop with return values to a 10-element sized single-dimensional array
Firebase ML Kit can perform face detection. It does however not perform face recognition. In other words: it can tell you that there is a face in a picture (and where it is), but it can’t tell you who it is. This makes it impossible to use ML Kit for authenticating a user. 3 solved … Read more
You are Calling Activity in a Background Thread Thats Why you are getting Error You Need to Call Like this Thread thread=new Thread(){ @Override public void run() { try { sleep(5*1000); runOnUiThread(new Runnable() { @Override public void run() { Intent i = new Intent(getApplicationContext(),MainActivity2.class); startActivity(i); } }); } catch (Exception ex) {} } }; thread.start(); … Read more
It’s because when you enter a number and press Enter key, scan.nextInt() consumes only the entered number, not the “end of line”. When scan.nextLine() executes, it consumes the “end of line” still in the buffer from the first input which you have provided during the execution of scan.nextInt() . Instead, use scan.nextLine() immediately after scan.nextInt(). … Read more
You can only cast a reference if there is an “is a” relationship. There is no “is a” relationship between A and B. A is a C, and B is a C, but B is not an A. Consider: Both apples (B) and oranges (A) are fruit (C), but apples are not oranges. Note: In … Read more
You do not need a regex for this, because a greedy algorithm will do. You can match a string against a pattern in O(n+p), where n is the length of string and p is the length of pattern, by following a very simple strategy: for each character of the pattern, look for a matching character … Read more
There are two basic approaches, the both kind of follow the same basic concept… Generate a list of images and paint them… You Could… Create a custom component which is singularly responsible for painting a single card. The benefit of this is that it’s generally easy to manage and uses what is already available. The … Read more
You should use r.nextInt(3); to get a number from the range 0-2. So, switch(r.nextInt(3)) { case 0: myVar = “a”; break; case 1: myVar = “b”; break; case 2: myVar = “c”; break; } 0 solved How do yo randomly assign a value to a variable? [closed]
for (Location l : RunicParadise.explorerLocations.values()) { **[NPE THROWN HERE] if (l.getWorld().getName().equals(loc.getWorld().getName())) {** So the one thing that wasn’t null here was the HashMap: explorerLocations. Otherwise you would have got the NPE on the previous line where you called HashMap.values(). Any of l, l.getWorld(), l.getWorld().getName(), loc, or loc.getWorld() could be null. You’re barking up the wrong … Read more
Thanks for your advices… Finally made it working.. thank you once again package practise; public class code{ public static void main(String[] args){ int[] Array = {5,8,6,4}; int[] newArray = new int[Array.length]; int a, b, c, d, e, f =1; for(int z : Array ){ d=0; for(int i=0; i<Array.length; i++){ a = z; b = Array[i]; … Read more
yes, your for loops ARE being skipped, since the second part of the for statement is not the break condition but the condition that has to be fullfilled for the loop to run. So it is NOT for(a = 0; a == 15; a += 3) but for(a = 0; a <= 15; a += … Read more
Try using input.next(); instead of input.nextLine(); Because input.nextLine(); advances this scanner past the current line and returns the input that was skipped. so if your input was 20, +, and 24, your method calc would get 20,24,null. 2 solved i cant get my calculator to work
For those with a maths background it is a surprising feature that System.out.println(“=” + (-3 % 4)); for example, returns -3 instead of 1 (which would be in the range [0,3]); Edit: in other words, the error message error message: Exception in thread “main” java.lang.ArrayIndexOutOfBoundsException: -8 is ultimately caused by (n % m) can return … Read more