All Flashcards
What is the key principle behind using a while loop?
To repeatedly execute a block of code as long as a specified condition remains true.
Why is it important to avoid infinite loops?
Infinite loops can crash your program by consuming resources indefinitely.
What is the purpose of a loop control variable?
To control the number of iterations in a loop and ensure it terminates correctly.
Explain the concept of a sentinel-controlled loop.
A loop that continues until a specific input (the sentinel) is entered, signaling the end of the loop.
Explain the concept of a flag-controlled loop.
A loop that continues until a specific condition is met within the loop, indicated by a flag variable.
What are the four loopy questions used for debugging loops?
- Does my loop start right? 2. Does my loop end right? 3. Does my loop make progress towards completion? 4. Will the method break in the middle of the loop?
How does exception handling make code more robust?
By preventing crashes due to runtime errors and allowing the program to gracefully handle unexpected situations.
What is the purpose of the throws keyword in a method signature?
It indicates that the method might throw a specific exception, which must be handled by the calling method.
What is the importance of initializing variables before using them in a loop?
Ensures that the loop starts with a known state and avoids unexpected behavior.
Explain the difference between a skipped loop and an infinite loop.
A skipped loop never executes because the condition is initially false, while an infinite loop never terminates because the condition is always true.
How are while loops used in input validation?
To repeatedly prompt the user for input until a valid input is provided.
How are while loops used in game development?
To maintain the game loop, continuously updating the game state and rendering the graphics.
How are while loops used in data processing?
To iterate through large datasets, performing operations on each element until the end of the data is reached.
How can while loops be used to simulate real-world processes?
By modeling repetitive tasks or events that continue until a specific condition is met, such as a machine running until it runs out of material.
How are while loops used in file processing?
To read and process data from a file line by line until the end of the file is reached.
How is exception handling used in real-world banking systems?
To handle situations like insufficient funds, invalid account numbers, or network errors during transactions, ensuring data integrity and system stability.
How are while loops used in operating systems?
To continuously monitor system resources and respond to events, such as handling user input or managing processes.
What does the following code output?
java
int i = 0;
while (i < 5) {
System.out.println(i);
i++;
}
0 1 2 3 4
Identify the error in the following code:
java
int i = 0;
while (i < 5) {
System.out.println(i);
}
The loop will run infinitely because the value of i is never updated.
What does the following code output?
java
int i = 5;
while (i > 0) {
System.out.println(i);
i--;
}
5 4 3 2 1
Identify the error in the following code:
java
int i = 10;
while (i > 0);
{
System.out.println(i);
i--;
}
The semicolon after the while condition creates an empty loop, and the subsequent block is executed only once.
What does the following code output?
java
int i = 0;
while (i < 10) {
if (i % 2 == 0) {
System.out.println(i + " is even");
}
i++;
}
0 is even 2 is even 4 is even 6 is even 8 is even
Identify the error in the following code:
java
int i = 0;
while (i < 5) {
System.out.println(i);
i++;
if (i == 3) {
break;
}
}
No error. This code will print 0, 1, and 2, then exit the loop.
What does the following code output?
java
int i = 0;
while (i < 5) {
i++;
if (i == 3) {
continue;
}
System.out.println(i);
}
1 2 4 5
Identify the error in the following code:
java
int number = -5;
while (number > 0) {
System.out.println(number);
number--;
}
The loop condition is initially false, so the loop body will never execute.
What does the following code output?
java
int i = 0;
while (true) {
System.out.println(i);
i++;
if (i > 5) {
break;
}
}
0 1 2 3 4 5
Identify the error in the following code:
java
int i = 0;
while (i < 5) {
System.out.println(i++);
}
No error. This code will print 0, 1, 2, 3, and 4.
What does the following code output?
java
int x = 10;
try {
int result = x / 0;
System.out.println("Result: " + result);
} catch (ArithmeticException e) {
System.out.println("Error: Division by zero");
}
Error: Division by zero