All Flashcards
How are conditional statements applied in real-world scenarios?
Controlling traffic lights, validating user input, decision-making in games.
How are loops applied in real-world scenarios?
Iterating through data in a database, repeating actions in a game, processing elements in an array.
How are Strings applied in real-world scenarios?
Storing and manipulating text data, processing user input, representing names and addresses.
How are Arrays applied in real-world scenarios?
Storing lists of items, representing game boards, managing collections of data.
How are Classes and Objects applied in real-world scenarios?
Modeling real-world entities (e.g., cars, people, bank accounts) in software.
How is Inheritance and Polymorphism applied in real-world scenarios?
Creating a hierarchy of animal classes where each animal makes a different sound, but all are treated as animals.
What are the differences between 'for' and 'while' loops?
For: Used when the number of iterations is known. While: Used when the number of iterations is unknown, and depends on a condition.
What are the differences between == and .equals() when comparing strings?
==: Compares object references (memory locations). .equals(): Compares the content of the strings.
What are the differences between inheritance and polymorphism?
Inheritance: Allows code reuse and creates an 'is-a' relationship. Polymorphism: Allows objects of different classes to be treated as objects of a common type.
What does the following code output?
java
int x = 10;
if (x > 5) {
x = x * 2;
}
System.out.println(x);
20
What does the following code output?
java
int i = 0;
while (i < 4) {
System.out.print(i + " ");
i++;
}
0 1 2 3
What does the following code output?
java
String str = "Hello";
System.out.println(str.substring(1, 4));
ell
What does the following code output?
java
int[] arr = {5, 10, 15};
System.out.println(arr[1]);
10
What does the following code output?
java
String s1 = "Java";
String s2 = "Java";
System.out.println(s1.equals(s2));
true
What does the following code output?
java
int sum = 0;
for (int i = 1; i <= 3; i++) {
sum += i;
}
System.out.println(sum);
6
What does the following code output?
java
String str = "Computer";
System.out.println(str.length());
8
Identify the error in the following code:
java
int[] arr = new int[3];
System.out.println(arr[3]);
ArrayIndexOutOfBoundsException: Index 3 is out of bounds for an array of length 3.
What does the following code output?
java
int x = 3;
if (x % 2 != 0) {
System.out.println("Odd");
} else {
System.out.println("Even");
}
Odd
What does the following code output?
java
String str = "Hello World";
System.out.println(str.indexOf("World"));
6