Loop counter is not incrementing

Question

I’m having a hard time finding the error in a logic that I use for traversing an arraylist.

  List<Caneta> canetas = new ArrayList<>(); 
  canetas.add(c1);
  canetas.add(c2);

  System.out.print(Arrays.toString(canetas.toArray()));

  for (Caneta caneta : canetas) {
    int x = 0;
    System.out.printf(canetas.get(x).getModelo());
    x++; 
  }

The Sout returns me the same answer, as if the x had not self-improved, could someone explain the problem to me? Grateful.

Answer 1

The x is being initialized within the foreach. In this way, with each iteration (loop) it is initialized with the value 0.

The solution would be to declare the x outside the loop.

int x = 0;
for (Caneta caneta : canetas) {
    System.out.printf(canetas.get(x).getModelo());
    x++; 
}

Although the above code is right, it doesn’t make much sense. The foreach is used to "pass" through all the elements of a collection and, at each loop, feed the variable (caneta, in case) with a list item.

So if you need to use the get(x), it would be better to use a for.

for(int x = 0; i < canetas.size(), x++) {
    System.out.printf(canetas.get(x).getModelo());
}

Or, if you want to continue using the "foreach", should do so

for(Caneta caneta : canetas){
     System.out.printf(caneta.getModelo());
}

You might be interested in reading this question: What are the syntax of the for loop in java?

Answer 2

Try this way:

  List<Caneta> canetas = new ArrayList<>(); 
  canetas.add(c1);
  canetas.add(c2);

  System.out.print(Arrays.toString(canetas.toArray()));

  for (Caneta caneta : canetas) {
    System.out.printf(caneta.getModelo());
  }