ArrayLists, 2D arrays, inheritance, and recursion concepts tested on AP Computer Science A.
35 cards · basic cards · AI-written, checked twice. Edit anything.
- What is an ArrayList in Java?
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A resizable array that can grow or shrink dynamically at runtime- How does an ArrayList differ from a regular array?
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ArrayList is resizable and part of the Collections Framework, while arrays have a fixed size set at creation- What method adds an element to an ArrayList?
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add()- What method removes an element from an ArrayList by index?
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remove()- What method accesses an element in an ArrayList at a specific index?
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get()- What import statement is required to use ArrayList?
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import java.util.ArrayList;- What does the size() method return for an ArrayList?
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The number of elements currently in the ArrayList- What exception is thrown when accessing an invalid ArrayList index?
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IndexOutOfBoundsException- What is the time complexity of accessing an ArrayList element by index?
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O(1) - constant time- What is a 2D array?
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An array of arrays, organized in rows and columns like a table or matrix- How do you declare a 2D array of integers named matrix with 3 rows and 4 columns?
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int[][] matrix = new int[3][4];- How do you access the element at row 1, column 2 in a 2D array?
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array[1][2]- What does matrix.length return for a 2D array?
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The number of rows in the 2D array- What does matrix[0].length return for a 2D array?
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The number of columns in the first row- What is a ragged array?
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A 2D array where rows can have different numbers of columns
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