0

Java Programming Language Quiz - 2

Description: Java Programming Language Quiz - 2
Number of Questions: 8
Created by:
Tags: java
Attempted 0/8 Correct 0 Score 0
  1. null

  2. 43

  3. x 2

  4. print()


Correct Option: C
Explanation:

It's a compound expression consisting of simple expression x (variable name), the addition operator ( ), and simple expression 2 (a 32-bit integer literal).

Which one of the following escape sequences cannot appear in a string literal?

  1. \f

  2. \u

  3. \"

  4. \\


Correct Option: B
Explanation:

\u must be followed by four hexadecimal digits and is then known as a Unicode escape sequence.

Which one of the following is not a widening conversion rule?

  1. Short integer to character

  2. Integer to long integer

  3. Floating-point to double precision floating-point

  4. Character to floating-point


Correct Option: A

AI Explanation

To answer this question, you need to understand the concept of widening conversions. Widening conversions are conversions that do not result in any loss of data or precision. Let's go through each option to understand why it is correct or incorrect:

Option A) Short integer to character - This option is incorrect because it is a valid widening conversion rule. When a short integer is converted to a character, it is promoted to an int first and then converted to a character.

Option B) Integer to long integer - This option is incorrect because it is a valid widening conversion rule. When an integer is converted to a long integer, it is promoted to a long integer without any loss of data or precision.

Option C) Floating-point to double precision floating-point - This option is incorrect because it is a valid widening conversion rule. When a floating-point value is converted to a double precision floating-point value, it is promoted to a double precision floating-point without any loss of data or precision.

Option D) Character to floating-point - This option is correct because it is not a valid widening conversion rule. Converting a character to a floating-point value is considered a narrowing conversion, as it can result in a loss of data or precision.

Therefore, the correct answer is Option D. This option is not a widening conversion rule because it involves a narrowing conversion.

The ?: operator is an example of which kind of operator?

  1. Binary

  2. Prefix

  3. Postfix

  4. Infix


Correct Option: D

Which one of the following operators offers the fastest way to divide a negative integer by 2 and keep the negative result (e.g., -4/2 equals -2)?

  1. /

  2. %

  3. >>

  4. >>>


Correct Option: C

You read the following statement in a Java program that compiles and executes.

submarine.dive(depth);

What can you say for sure?

  1. depth must be an int

  2. dive must be a method.

  3. dive must be the name of an instance field.

  4. submarine must be the name of a class

  5. submarine must be a method.


Correct Option: B

Given the following class definition, which of the following methods could be legally placed after the comment //Here public class Rid{ public void amethod(int i, String s){} //Here }

  1. public void amethod(int s, String i){}

  2. public void Amethod(int i, String s) {}

  3. public void amethod(int i, String mystring){}

  4. None of the above

  5. public int amethod(int i, String s){}


Correct Option: B

Which of the following statements are true?

  1. Strings are a primitive type in Java and the StringBuffer is used as the matching wrapper type

  2. The size of a string can be retrieved using the length property.

  3. Strings are a primitive type in Java that overloads the + operator for concatenation

  4. The String class is implemented as a char array, elements are addressed using the stringname[] convention


Correct Option: C

AI Explanation

To answer this question, let's go through each option to understand why it is correct or incorrect:

Option A) Strings are a primitive type in Java and the StringBuffer is used as the matching wrapper type. This option is incorrect because strings are not primitive types in Java. They are objects of the String class, which is part of the Java API. The StringBuffer class is used for mutable strings, but it is not a wrapper type for strings.

Option B) The size of a string can be retrieved using the length property. This option is correct. In Java, the length() method is used to get the number of characters in a string.

Option C) Strings are a primitive type in Java that overloads the + operator for concatenation. This option is correct. In Java, strings are not primitive types, but they are treated as first-class citizens and have a special syntax for concatenation using the + operator.

Option D) The String class is implemented as a char array, elements are addressed using the stringname[] convention. This option is incorrect. While the String class does contain a char array internally, the elements of the array cannot be directly addressed using the stringname[] convention. Instead, you need to use methods provided by the String class to access or manipulate the characters.

The correct answer is C. Strings are not primitive types in Java but are treated as such and overload the + operator for concatenation.

- Hide questions