Answer:

int[] scores = new double[25];

scores[ 0 ] OK
scores[ 1 ] OK
scores[ -1 ] illegal
scores[ 10] OK
scores[ 25 ] illegal
scores[ 24 ] OK
scores[ 1.2] illegal
scores [2] OK
scores [ 4 ] OK

Notice that there may be spaces between the reference variable name and the first bracket [ . Usually this is not done, however.

Array Initialization

Lacking any other information, the cells of an array are initialized to the default value for their type. Each cell of a numeric array is initialized to zero.

Each cell of an array of object references is initialized to null. (Arrays of object references are discussed in an upcoming chapter.)

Of course, the program can assign values to cells after the array has been constructed. In the following, the array object is constructed and each cell is initialized to 0. Then some assignment statements explicitly change some cells:

class ArrayEg1
{
  public static void main ( String[] args )
  {
    int[] stuff = new int[5];

    stuff[0] = 23;
    stuff[1] = 38;
    stuff[2] = 7*2;

    System.out.println("stuff[0] has " + stuff[0] );
    System.out.println("stuff[1] has " + stuff[1] );
    System.out.println("stuff[2] has " + stuff[2] );
    System.out.println("stuff[3] has " + stuff[3] );
    System.out.println("stuff[4] has " + stuff[4] );
  }
}

QUESTION 7:

What does the program write?

stuff[0] has
stuff[1] has
stuff[2] has
stuff[3] has
stuff[4] has