PRELIM DSAA Flashcards by LUIS KEINE CERTEZA

What is a data structure?

A) A way to store and organize data
B) A type of programming language
C) A part of the operating system
D) A machine learning algorithm

A way to store and organize data

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Which of the following is NOT a goal of data structures?

A) Correctness
B) Efficiency
C) Randomness
D) Fast searching and sorting

Randomness

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What is an entity in data structures?

A) A specific type of file
B) A class of objects with attributes
C) A field in a database
D) A function in Java

A class of objects with attributes

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Which of the following is a collection of various records of one type of entity?

A) Field
B) File
C) Record
D) Data

File

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What is an array?

A) A collection of variables with different data types
B) A collection of items stored in contiguous memory locations
C) A dynamic data structure
D) A type of linked list

A collection of items stored in contiguous memory locations

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Which of the following statements about arrays is true?

A) Arrays can store only primitive data types
B) Arrays are always dynamically resizable
C) Arrays can contain objects as well as primitive types
D) Arrays use linked nodes for storage

Arrays can contain objects as well as primitive types

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What is the index of the last element in an array of size 10?

A) 9
B) 10
C) 0
D) 1

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What will happen if you try to access an index that is out of bounds in Java?

A) The program runs normally
B) The array automatically resizes
C) An ArrayIndexOutOfBoundsException is thrown
D) The compiler converts it to the nearest valid index

An ArrayIndexOutOfBoundsException is thrown

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Which Java package contains the ArrayList class?

A) java.lang
B) java.util
C) java.io
D) java.math

java.util

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Which of the following is true about ArrayLists?

A) They are static in size
B) They use dynamic memory allocation
C) They do not allow duplicates
D) They store elements in a tree structure

They use dynamic memory allocation

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What is the difference between an Array and an ArrayList?
A) Array has a fixed size, while ArrayList can grow dynamically
B) Array stores only objects, while ArrayList stores only primitive types
C) Array is a class, while ArrayList is a function
D) They are both identical

Array has a fixed size, while ArrayList can grow dynamically

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Which method is used to remove an element from an ArrayList at a specific index?
A) remove(index)
B) delete(index)
C) erase(index)
D) clear(index)

remove(index)

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What principle does a stack follow?
A) First In, First Out (FIFO)
B) Last In, First Out (LIFO)
C) Random access retrieval
D) Hierarchical storage

Last In, First Out (LIFO)

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Which operation adds an element to the top of the stack?
A) enqueue()
B) pop()
C) push()
D) insert()

push()

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Which operation removes the top element from the stack?
A) delete()
B) dequeue()
C) pop()
D) remove()

pop()

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What does the peek() method do in a stack?
A) Removes the top element
B) Returns the top element without removing it
C) Searches for an element
D) Returns the size of the stack

Returns the top element without removing it

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Which method checks if a stack is empty?
A) isEmpty()
B) clear()
C) hasElements()
D) exists()

isEmpty()

Which of the following is an example of an application of stacks?
A) Database indexing
B) Job scheduling
C) Infix to Postfix conversion
D) Network routing

Infix to Postfix conversion

Which of the following is true about the Stack class in Java?
A) It extends the ArrayList class
B) It implements the Queue interface
C) It extends the Vector class
D) It does not allow duplicate elements

It extends the Vector class

What is the main purpose of studying data structures?

A) To learn new programming languages
B) To understand how data is organized and managed efficiently
C) To improve network security
D) To create hardware components

To understand how data is organized and managed efficiently

What defines a data structure?

A) A structural representation of the logical relationship between data elements
B) A type of database management system
C) A high-level programming language
D) A type of file system

A structural representation of the logical relationship between data elements

Which of the following is NOT a feature of data structures?

A) Data storage
B) Data organization
C) Data destruction
D) Data retrieval

Data destruction

What is an entity in data structures?

A) A data type
B) A class of objects with attributes
C) A function in Java
D) A type of array

A class of objects with attributes

Which term refers to a collection of various data items?

A) Field
B) Record
C) File
D) Group

Record

What is a field in data structures? A) A collection of related records B) A single unit of information representing an attribute C) A type of linked list D) A database query

A single unit of information representing an attribute

Which of the following best describes a file? A) A collection of various records of one type of entity B) A function that stores data in memory C) A group of related fields D) A type of primitive data structure

A collection of various records of one type of entity

What is an array? A) A collection of elements stored in contiguous memory locations B) A dynamic data structure that can change size C) A linked list of data elements D) A collection of unrelated data types

A collection of elements stored in contiguous memory locations

Which of the following statements about arrays is FALSE? A) Arrays are fixed in size once declared B) Arrays store elements of the same data type C) Arrays can store elements at non-contiguous memory locations D) Arrays allow indexed access to elements

Arrays can store elements at non-contiguous memory locations

How are elements accessed in an array? A) Using a linked list traversal B) Using an index C) Using a hash function D) Using binary search

Using an index

What is the index of the first element in an array? A) 0 B) 1 C) -1 D) n-1

Which operation retrieves an element from an array? A) insert() B) delete() C) get(index) D) update()

get(index)

Which package contains the ArrayList class in Java? A) java.lang B) java.util C) java.io D) java.math

java.util

What makes an ArrayList different from an array? A) It can store primitive data types directly B) It has a fixed size C) It dynamically resizes D) It does not allow duplicates

It dynamically resizes

Which method adds an element to an ArrayList? A) insert() B) add() C) append() D) push()

add()

Which method removes an element from an ArrayList? A) delete() B) remove() C) erase() D) clear()

remove()

What is the principle of a stack? A) First In, First Out (FIFO) B) Last In, First Out (LIFO) C) Random access retrieval D) Hierarchical storage

Last In, First Out (LIFO)

Which operation inserts an element into a stack? A) enqueue() B) pop() C) push() D) insert()

push()

Which method removes the top element of the stack? A) delete() B) pop() C) remove() D) extract()

pop()

What does the peek() method do in a stack? A) Removes the top element B) Returns the top element without removing it C) Searches for an element D) Returns the size of the stack

Returns the top element without removing it

Which stack method checks if the stack is empty? A) isEmpty() B) clear() C) hasElements() D) exists()

isEmpty()

Which is a common application of stacks? A) Sorting data B) Database indexing C) Infix to Postfix conversion D) Network routing

Infix to Postfix conversion