Scope

Code blocks define scope, which is where a variable is available:

  int i = 0;
  while (i < 5) {
    int iTimesTwo = 2 * i;
    System.out.println(iTimesTwo);
    i = i + 1;
  }
  // iTimesTwo is no longer available, i.e. "out of scope"
  System.out.println("i is still in scope with value " + i);

This is true for any code block, such as in an if statement.

  boolean theTest = true;
  if (theTest) {
    String ifMessage = "In if block's scope";
  }
  System.out.println(ifMessage);  // DOES NOT COMPILE.
                                  // ifMessage was declared inside the if block
                                  // so it is not available here.

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