Programming Fundamentals/Arrays/Dynamic Arrays
A dynamic array is a random access, variable-size list data structure that allows elements to be added or removed. This activity introduces dynamic arrays. This activity will help you understand how to use dynamic arrays in a program.
Objectives[edit | edit source]
- Understand dynamic array concepts
- Understand how dynamic array elements are added in a program.
- Use a for loop to assign and display array values.
Prerequisites[edit | edit source]
Introduction[edit | edit source]
Review the following pseudocode.
Declare Integer values Declare Integer value For index = 0 To 2 Output "Enter value " + (index + 1) + ":" Input value values.add(value) End For For index = 0 To 2 Output values[index] End For
Questions[edit | edit source]
- What syntax is used to define dynamic arrays in your preferred programming language?
- What syntax is used to add dynamic array elements in your preferred programming language?
Activity[edit | edit source]
With a partner, use Repl.it or your preferred integrated development environment (IDE) to create a program based on the pseudocode above.
- Start by declaring an empty dynamic array.
- Create a for loop to input three values into the array.
- Create a for loop to display the array values.
- Save the program.
- Test the program to verify that it works correctly.
- Trade places, so that both partners have an opportunity to "drive" the programming environment.
- Modify the program to increase the number of values in the array.
- Modify the program to decrease the number of values in the array.
- Experiment with using the wrong starting or ending index values in the for loop (For example, 1 to 3 rather than 0 to 2).
- Working together, create a list of changes that might be made to use dynamic arrays in programs you've already written. What parts could be replaced with a dynamic array? When should a dynamic array be used rather than a fixed-length array?
Applications[edit | edit source]
- Identify specific steps which must be followed when creating a program using dynamic arrays.
- Discuss your activity experience with your classmates. What surprised you? What have you learned that you can apply to your own school or work environment?