Multiple choice technology programming languages

Which of the following are valid declarations?

  1. int i = 0XCAFE;

  2. boolean b = 0;

  3. char c = A;

  4. byte b = 128;

  5. char c = "A";
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Option A is valid: '0XCAFE' is a hexadecimal literal (hex digits start with 0X or 0x). Option B is invalid: boolean can only be 'true' or 'false', not 0. Option C is invalid: 'A' must be quoted as a character literal. Option D is invalid: byte range is -128 to 127, 128 overflows. Option E is invalid: char can't take a String literal.

AI explanation

To determine which of the given options are valid declarations, let's analyze each option:

A. int i = 0XCAFE; This option is a valid declaration. In Java, the prefix "0X" indicates a hexadecimal value. The hexadecimal value 0XCAFE is a valid integer value.

B. boolean b = 0; This option is not a valid declaration. In Java, the boolean data type can only have two possible values: true or false. Assigning an integer value of 0 to a boolean variable is not allowed.

C. char c = A; This option is not a valid declaration. In Java, character literals should be enclosed in single quotes (''). The character literal 'A' represents the character 'A', so the correct declaration would be char c = 'A';.

D. byte b = 128; This option is not a valid declaration. In Java, the byte data type can hold values from -128 to 127. Assigning the value 128 to a byte variable exceeds the range of valid values.

E. char c = "A"; This option is not a valid declaration. In Java, character literals should be enclosed in single quotes (''). The double quotes ("") are used for string literals. To assign the character 'A' to a char variable, the correct declaration would be char c = 'A';.

Therefore, the valid declaration among the given options is A) int i = 0XCAFE.

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