Converting an integer to a string MCQ

 Here are multiple-choice questions (MCQs) on converting an integer to a string in Java:

Question 1

Which of the following methods can be used to convert an integer to a string in Java?

A) Integer.toString()

B) String.valueOf()

C) Integer.toString(int)

D) All of the above

Answer: D) All of the above

Question 2

What will be the output of the following code?

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int number = 123;

String str = Integer.toString(number);

System.out.println(str);

A) 123

B) "123"

C) Error

D) null

Answer: B) "123"

Question 3

Which method is more efficient for converting an integer to a string, String.valueOf() or Integer.toString()?

A) String.valueOf() is more efficient.

B) Integer.toString() is more efficient.

C) Both are equally efficient.

D) new String(int) is more efficient.

Answer: C) Both are equally efficient.

Question 4

What will the following code return?

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String str = String.valueOf(456);

A) "456"

B) 456

C) null

D) Error

Answer: A) "456"

Question 5

What does the following code do?

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int num = 789;

String str = "" + num;

A) Converts the integer 789 to a string "789" by concatenation.

B) Converts the integer 789 to a string "789" using String.valueOf().

C) Results in a compilation error.

D) Converts the integer 789 to a string "789" using Integer.toString().

Answer: A) Converts the integer 789 to a string "789" by concatenation.

Question 6

What is the output of the following code?

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int number = 0;

String str = Integer.toString(number);

System.out.println(str);

A) "0"

B) 0

C) null

D) "null"

Answer: A) "0"

Question 7

Which of the following is NOT a valid way to convert an integer to a string in Java?

A) Integer.toString(int)

B) String.valueOf(int)

C) Integer.toString()

D) "" + int

Answer: C) Integer.toString()

Question 8

What is the result of the following code?

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String str = Integer.toString(1234, 2);

A) "1234"

B) "1234" in binary

C) "10011010010"

D) Error

Answer: C) "10011010010"

Question 9

Can the String.valueOf() method convert an integer array to a string?

A) Yes, it converts each element to a string.

B) No, it throws an exception.

C) Yes, it converts the array's memory address to a string.

D) No, it returns "null".

Answer: C) Yes, it converts the array's memory address to a string.

Question 10

What will be the output of the following code?

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int num = 2147483647;

String str = Integer.toString(num);

System.out.println(str);

A) "2147483647"

B) 2147483647

C) -2147483647

D) Error

Answer: A) "2147483647"

Question 11

Which of the following can be used to convert an integer to a string with a specific radix?

A) String.valueOf(int, int)

B) Integer.toString(int, int)

C) String.valueOf(int, radix)

D) Integer.parseInt(int, int)

Answer: B) Integer.toString(int, int)

Question 12

What does the following code do?

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String str = String.valueOf(0);

A) Converts the integer 0 to the string "0".

B) Converts the integer 0 to the string "null".

C) Throws a NullPointerException.

D) Does not compile.

Answer: A) Converts the integer 0 to the string "0".

Question 13

What will be the output of the following code?

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int num = -123;

String str = Integer.toString(num);

System.out.println(str);

A) "123"

B) "-123"

C) "0"

D) Error

Answer: B) "-123"

Question 14

What is the result of Integer.toString(10, 16)?

A) "10"

B) "A"

C) "16"

D) "10" in hexadecimal

Answer: B) "A"

Question 15

Can you use String.valueOf() to convert a primitive int to a string?

A) Yes

B) No

C) Only with autoboxing

D) Only if the int is not null

Answer: A) Yes

Question 16

Which method provides more control over the conversion of an int to a string?

A) Integer.parseInt()

B) Integer.toString()

C) String.valueOf()

D) Both B and C

Answer: B) Integer.toString()

Question 17

What is the return type of Integer.toString(int)?

A) int

B) String

C) Integer

D) void

Answer: B) String

Question 18

What will the following code output?

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String str = Integer.toString(-32768);

System.out.println(str);

A) "32768"

B) "-32768"

C) "0"

D) Error

Answer: B) "-32768"

Question 19

Which method can be used to convert an integer to a string representation in a different number system, like binary?

A) Integer.toBinaryString(int)

B) Integer.toString(int, 2)

C) String.valueOf(int, 2)

D) A and B

Answer: D) A and B

Question 20

What happens if Integer.toString() is called with an integer value that exceeds Integer.MAX_VALUE?

A) It throws an exception.

B) It returns "2147483647".

C) It returns the string representation of Integer.MAX_VALUE.

D) This scenario is impossible; integers can't exceed Integer.MAX_VALUE.

Answer: D) This scenario is impossible; integers can't exceed Integer.MAX_VALUE.