3CSE2 Lab Day-7

What is the primary purpose of StringBuffer in Java?

• The primary purpose of StringBuffer in Java is to provide a mutable sequence of characters for efficient string manipulation.

• To create immutable strings in Java.

• To store a fixed number of characters.

• To provide a method for string comparison.

How does StringBuilder improve performance over StringBuffer?

• StringBuilder automatically manages memory allocation, unlike StringBuffer.

• StringBuilder is synchronized, making it safer for multi-threaded environments.

• StringBuilder improves performance over StringBuffer by being non-synchronized, reducing overhead in single-threaded environments.

• StringBuilder uses more memory than StringBuffer, leading to slower performance.

Which method in StringTokenizer is used to check if there are more tokens?

• getTokenCount

• hasMoreTokens

• nextToken

• isTokenAvailable

What is the difference between StringBuffer and StringBuilder in terms of thread safety?

• Both StringBuffer and StringBuilder are thread-safe.

• StringBuffer is faster than StringBuilder.

• StringBuffer is thread-safe; StringBuilder is not.

• StringBuilder is thread-safe; StringBuffer is not.

How can you convert a StringTokenizer to an array of strings?

• Convert the StringTokenizer to a List using Collections.list().

• Use a loop to collect tokens into a List, then convert it to an array with list.toArray(new String[0]).

• Use String.split() method directly on the string.

• Call the toArray() method on the StringTokenizer instance.

What method would you use to append a string to a StringBuilder?

• stringBuilder.insert("yourString");

• stringBuilder.addString("yourString");

• stringBuilder.concat("yourString");

• stringBuilder.append("yourString");

Explain how String manipulation can affect performance in Java applications.

• String operations are faster than primitive data types.

• String manipulation has no impact on performance.

• String manipulation can lead to performance issues due to object creation overhead and memory usage.

• Using StringBuilder always improves performance.

What is the default capacity of a StringBuilder when it is created?

• 64

• 8

• 32

• 16

How do you split a string into tokens using StringTokenizer?

• Use StringTokenizer tokenizer = new StringTokenizer(string, delimiter); while (tokenizer.hasMoreTokens()) { String token = tokenizer.nextToken(); }

• Use String.split(delimiter) to get tokens.

• Use StringTokenizer to count the number of characters in the string.

• Use StringTokenizer(string) without a delimiter.

In what scenarios would you prefer using StringBuilder over StringBuffer?

• Use StringBuffer in single-threaded scenarios for better performance.

• StringBuilder is preferred in multi-threaded environments.

• StringBuffer is faster than StringBuilder in all cases.

• Use StringBuilder in single-threaded scenarios for better performance.