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IB CS Sample Test - Unit 1

Please write your answers in the answer booklet. Carefully label each problem with the problem number so that I can find the answers. You do not need to rewrite the questions.

  1. (2 marks) Name two examples of computer hardware.

  2. (3 marks) Name three common native data types in programming languages.

  3. (2 marks) What does the operator ++ do in code such as a++?

  4. (1 mark) What would be the outcome of the statement 2 * 3 > 4 && 2 + 3 >= 5?

  5. (2 mark) Describe what it means for a programming language to be “statically typed” and describe one advantage of static typing.

  6. (2 marks) Recently my son asked me how my car worked. “Well,” I said, “when I push the pedal the engine burns gasoline, making a bunch of tiny explosions that move some rods that make the wheels turn. There’s more to it than that, but that’s all I know.” This explanation is an example of what computer science principle? Briefly explain your answer.

  7. (2 marks) Outline the relationship between RAM and cache.

  8. (1 mark) How many bits are in a byte?

  9. Programmers who work at a very low level with computer processors might write in a language like the one below:

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    mov   eax,3
mov   ebx,5
add   eax,ebx
int   0x80

    a. (1 mark) This is an example of what type of language?
    b. (1 mark) The command mov tells the processor to move a value into a register. What is a CPU register? c. (1 mark) Moving to registers and adding values are examples of the _______ of the processor.

  10. (5 marks) Construct a complete trace table for the script below for the input values N = 9 and T = 14, showing all variable values and all outputs of the script.

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    J = N + T
K = J div 2
loop while K >= N
    Output (K - N)
    K = K - 1
end loop

  11. (5 marks) Construct an algorithm (in pseudocode or typescript-like pseudocode) to loop through the elements of a string array with the name MONKEYS, outputting the sentence Monkey number _____ has the name _____ for each monkey, as shown in the example below.

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    Input: [Napolean, Ricky]
Output:
  Monkey number 1 has the name Napolean
  Monkey number 2 has the name Ricky

  12. Consider the java method below:

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     public double mystery(double n, boolean b) {
   if (b && n > 10) {
       return n;
   }else {
       return n % 2;
   }
}

    1. (1 mark) What is the return type of this method?

    2. (1 mark) What does the operator % do?

    3. (4 marks) For each method call, write the output. If the method would result in an error, write “error”.

      1. mystery(12.3, true);

      2. mystery(87, "false");

  13. Consider an IB collection of numbers NUMS = {2, 7, -3, 11, 15, -3}

    1. (4 marks) Consider the following algorithm

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      NUMS.resetNext()
CL = 0
loop while NUMS.hasNext()
    if NUMS.getNext() = -3 then
        CL = CL + 1
    end if
end loop
output CL

      For this algorithm copy and complete the following started trace table:

      CL NUMS.hasNext() NUMS.getNext() = -3 output
      0 TRUE FALSE  
      … … … …

    2. (3 marks) Construct an algorithm using pseudocode that returns the sum of the elements