public class IntArray {

    public static void main (String [] args) {
	// creating a new array of length 5
	int [] a = new int[5];

	// printing out the contents of a (all 0s):
	for (int i = 0; i < a.length; ++i) {
	    System.out.println("a[" + i + "] = " + a[i]);
	}
	
	// storing some data in the array:
	for (int i = 0; i < a.length; ++i) {
	    a[i] = i * i;
	}

	// printing out the contents of a after the assignment:
	System.out.println("a after the assignment:");
	for (int i = 0; i < a.length; ++i) {
	    System.out.println("a[" + i + "] = " + a[i]);
	}
	
	// counting the number of elements in a which are < 10:
	int count = 0;
	for (int i = 0; i < a.length; ++i) {
	    if (a[i] < 10) count++;
	}
	System.out.println(count + " elements are less than 10");

	// creating another array (of length 'count')
	int [] b = new int[count];
	
	// copy elements from a into b (note: b is shorter)
	for (int i = 0; i < b.length; ++i) {
	    b[i] = a[i];
	}

	// print out b:
	System.out.println("array b:");
	for (int i = 0; i < b.length; ++i) {
	    System.out.println("b[" + i + "] = " + b[i]);
	}

	// change a:
	for (int i = 0; i < a.length; ++i) {
	    a[i] = a[i] - i;
	}
	
	// print out a:
	System.out.println("a after the change:");
	for (int i = 0; i < a.length; ++i) {
	    System.out.println("a[" + i + "] = " + a[i]);
	}

	// print out b:
	System.out.println("array b after a has changed:");
	for (int i = 0; i < b.length; ++i) {
	    System.out.println("b[" + i + "] = " + b[i]);
	}
	
    }   
}