To solve this question, the user needs to understand the logic of the do-while loop and the post/pre-increment and decrement operators.

The given code initializes two integer variables x and y to 0 and 10, respectively. Then, it enters a do-while loop with the condition x < 5. Inside the loop, the value of y is decremented by 1, and the value of x is incremented by 1. This process continues until the value of x becomes greater than or equal to 5. Finally, it prints the values of x and y.

Now, let's go through each option and explain why it is right or wrong:

A. 5,6: This option is incorrect because the loop stops when the value of x becomes 5, at which point y is equal to 5, not 6.

B. 5,5: This option is correct. The loop stops when the value of x becomes 5, at which point y is also equal to 5.

C. 6,5: This option is incorrect because the loop stops when the value of x becomes 5, at which point x is equal to 5, not 6.

D. 6,6: This option is incorrect because the loop stops when the value of x becomes 5, at which point x is equal to 5, and y is equal to 5.

Therefore, the correct answer is:

The Answer is: B

To solve this question, the user needs to know about while loop and comparison operators.

In the given code snippet, the while loop will only execute if the condition inside the parentheses is true. The code initializes the variable x to 12 and checks if it is less than 10. Since 12 is greater than 10, the condition is false, and the code inside the while loop will never execute. The print statement will execute outside of the loop, which will output the value of the variable x.

Options A, B, and C can be eliminated since none of them represent the correct value.

Option D is incorrect because the print statement will execute regardless of whether the while loop is executed or not.

Therefore, the correct answer is:

The Answer is: C. 12

To solve this question, the user needs to know that the given code is testing whether a string value is null or empty. They also need to know the syntax of if-else statements in Java.

Now, let's go through each option and explain why it is right or wrong:

A. null: This option is incorrect because the code checks if the string is null using the expression str == null, which evaluates to false since str is "null" (a non-null string literal).

B. zero: This option is incorrect because the code does not check if the string is empty using the expression str.length() == 0. Instead, it tries to use an invalid syntax by placing an else block after the if block. This leads to a compilation error.

C. some: This option is incorrect because the code won't reach this block due to the compilation error mentioned above.

D. Compilation fails: This option is correct. The code will fail to compile due to the invalid syntax in the else block. The correct syntax for an if-else statement is:

if (condition) {
    // code block for true case
} else {
    // code block for false case
}

Therefore, the correct code should be:

public static void main(String[] args) {
  String str = "null"; 
  if (str == null) {
    System.out.println("null");
  } else if (str.length() == 0) {
    System.out.println("zero");
  } else {
    System.out.println("some");
  }  
}

The Answer is: D