Question 1

A String constructor cannot be passed ________.

Accepted Answer

B

Question 2

Which of the following creates the string of the numbers from 1 to 1000 most efficiently?

Accepted Answer

Using a StringBuilder with an initial capacity that can accommodate the expected size of the final string (3000 in this case) avoids the need for resizing, making it more efficient than the other options.

Question 3

Which of the following is not a method of class String?

Accepted Answer

The correct method name for converting a string to a character array in Java is `toCharArray()`, not `toCharacterArray`. Therefore, option C is not a method of the String class.

Question 4

Given the following declaration:
StringBuilder buf = new StringBuilder();
What is the capacity of buf?

Accepted Answer

The default capacity of a StringBuilder is 16 characters. Therefore, the capacity of buf is 16.

Question 5

String objects are immutable.This means they ________.

Accepted Answer

Immutable means that once a string object is created, it cannot be changed. Any attempt to modify the contents of the original string results in the creation of a new string object with the modified content.

Question 6

StringBuilder objects can be used in place of String objects if ________.

Accepted Answer

All of the above conditions can be satisfied using StringBuilder objects. StringBuilder objects allow manipulation of string data that is not constant, they can handle a dynamic growth in string size and they provide more efficient concatenation compared to string concatenation.

Question 7

Consider the statement below:
StringBuilder sb1 = new StringBuilder("a toyota");
Which of the following creates a String object with the value "toy"?

Accepted Answer

The answer of Consider the statement below:
StringBuilder sb1 = new...

Question 8

The statement
S1)equalsIgnoreCase(s4)
Is equivalent to which of the following?

Accepted Answer

The method regionMatches() compares two strings within a specified range of character positions. The first argument is an index in the calling string (s1) from where the comparison starts. The second argument (true or false) specifies whether the comparison is case sensitive or not. The next two arguments are the index and length of the substring in the second string (s4) that needs to be compared with the substring in the first string. So, s1.regionMatches(true,0,s4,0,s4.length()) is the correct equivalent expression of s1.equalsIgnoreCase(s4) as it ignores the case differences and compares the entire substring of s4 with the starting index 0 of s1.

Question 9

Consider the examples below:
a)a string.
b)'a string'.
c)"a string".
d)"1234".
e)integer.
Which could be the value of a Java variable of type String?

Accepted Answer

The answer of Consider the examples below:
a)a string.
b)'a string'.
c)"a string".
d)"1234".
e)integer.
Which...

Question 10

Which of the following will create a String different from the other three?

Accepted Answer

The answer of Which of the following will create a...

Question 11

Given the following declarations:
StringBuilder buffer = new StringBuilder("Testing Testing");
Buffer.setLength(7);
Buffer.ensureCapacity(5);
Which of the following is true?

Accepted Answer

The answer of Given the following declarations:
StringBuilder buffer = new...

Question 12

Which of the following statements is true?

Accepted Answer

The capacity of a StringBuilder is the amount of memory allocated for it, while the length is the current number of characters in it. The capacity can be greater than or equal to the length, but the length cannot exceed the capacity. Therefore, statement C is true. Statements A and B are false.

Question 13

To find the character at a certain index position within a String,use the method ________.

Accepted Answer

To find the character at a certain index position within a String, we can use the method charAt() with the index as an argument. This method returns the character at the specified index position within the string. Options A and B are incorrect as there is no method getChars or getCharAt in the String class. Option D is also incorrect as charAt() takes the index as the argument, not the character we are searching for.

Question 14

Given the following declarations:
StringBuilder buf;
StringBuilder buf2 = new StringBuilder();
String c = new String("test");
Which of the following is not a valid StringBuilder constructor?

Accepted Answer

The StringBuilder constructor with two arguments does not take a StringBuilder as its first argument. Therefore, option B is not a valid constructor. The other three options are valid constructors. Option A constructs a StringBuilder with no initial characters. Option C constructs a StringBuilder with an initial capacity of 32 characters. Option D constructs a StringBuilder with the same contents as the String "test".

Question 15

An anonymous String ________.

Accepted Answer

An anonymous String is a string literal, which means it is a sequence of characters enclosed in double quotes and cannot be changed once it is created. It has a specific value associated with it. Option A is incorrect as it has a value. Option C is also wrong since anonymous String is immutable in nature. Therefore, the correct option is B.

Question 16

How many String objects are instantiated by the following code segment (not including the literals)?
String s1,output;
S1 = "hello";
Output = "
The string reversed is: " ;
For (int i = s1.length()- 1;i >= 0;i--)
Output += s1.charAt(i)+ " " ;

Accepted Answer

The answer of How many String objects are instantiated by...

Question 17

The length of a string can be determined by ________.

Accepted Answer

The length of a string can be determined using the String method length(). There is no instance variable length or method strlen() in the standard String class. Therefore, the correct answer is choice A.

Question 18

The statement
S1)startsWith("art")
Has the same result as which of the following?

Accepted Answer

All of the given options will return true if the first three characters of s1 are "art".

Question 19

Consider the String below:
String r = "a toyota";
Which of the following will create the String r1 = "a TOYOTa"?

Accepted Answer

The correct choice is C because it chains the replace method to replace all occurrences of 't', 'o', and 'y' with their uppercase counterparts. This will create the desired output of "a TOYOTa." Option A is incorrect because it only replaces part of the string and is missing quotation marks around the second parameter. Option B is incorrect because it only replaces the first occurrence of 't' with 'T', and the third option replaces a substring of the original string which is not what we want.

Question 20

The String method substring returns ________.

Accepted Answer

The substring method returns a portion of a String as another String.

Quiz 14: Strings

A String constructor cannot be passed ________.

Which of the following creates the string of the numbers from 1 to 1000 most efficiently?

Which of the following is not a method of class String?

Given the following declaration: StringBuilder buf = new StringBuilder() ; What is the capacity of buf?

String objects are immutable.This means they ________.

StringBuilder objects can be used in place of String objects if ________.

Consider the statement below: StringBuilder sb1 = new StringBuilder("a toyota") ; Which of the following creates a String object with the value "toy"?

The statement S1) equalsIgnoreCase(s4) Is equivalent to which of the following?

Consider the examples below: a) a string. b) 'a string'. c) "a string". d) "1234". e) integer. Which could be the value of a Java variable of type String?

Which of the following will create a String different from the other three?

Given the following declarations: StringBuilder buffer = new StringBuilder("Testing Testing") ; Buffer.setLength(7) ; Buffer.ensureCapacity(5) ; Which of the following is true?

Which of the following statements is true?

To find the character at a certain index position within a String,use the method ________.

Given the following declarations: StringBuilder buf; StringBuilder buf2 = new StringBuilder() ; String c = new String("test") ; Which of the following is not a valid StringBuilder constructor?

An anonymous String ________.

How many String objects are instantiated by the following code segment (not including the literals) ? String s1,output; S1 = "hello"; Output = "\nThe string reversed is: " ; For (int i = s1.length() - 1;i >= 0;i--) Output += s1.charAt(i) + " " ;

The length of a string can be determined by ________.

The statement S1) startsWith("art") Has the same result as which of the following?

Consider the String below: String r = "a toyota"; Which of the following will create the String r1 = "a TOYOTa"?

The String method substring returns ________.