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Working with HashSet

Create a HashSet to hold a list of heights in inches (Integer), add some new heights, and replace one of the heights with null (to see that Set allows for null objects).

This exercise is part of the course

Data Types and Exceptions in Java

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Exercise instructions

  • Import HashSet for use in the application.
  • Construct a new HashSet of Integers and set the heights variable to it.
  • Add a new height, 64, to the heights list.
  • Replace 64 with null.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

// Import HashSet
____ ____.____.____;

public class Sizes {

	public static void main(String[] args) {
    	// Create an HashSet of Integer using parameterized constructor
        ____<____> heights = ____ ____<____>();
		heights.add(72);
        // Add 64 to the set
        heights.____(____);
		heights.add(66);
		heights.remove(64);
        // Add null to the set
        ____.____(____);
		System.out.println(heights);
	}
}
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