If/Else Tracing

All 15 if/else tracing questions

Work through the interactive quiz above first. This is the full if/else tracing question set with worked solutions, so students can review any question after attempting it.

1. 1.Code Tracing 01 - If/Else Tracing: track the final printed value.

   int score = 18;
   if (score > 36)
     System.out.print("A");
   else if (score > 28)
     System.out.print("B");
   else if (score > 20)
     System.out.print("C");
   else
     System.out.print("D");

   • D
   • A
   • B
   • C
   Show worked solution

   Correct answer: D

   An if/else-if chain stops at the first true condition.

2. 2.Code Tracing 12 - If/Else Tracing: follow the variable updates.

   int change = -2;
   if (change > 0)
     System.out.print("up");
   else if (change < 0)
     System.out.print("down");
   else
     System.out.print("same");

   • The code does not compile.
   • down
   • up
   • same
   Show worked solution

   Correct answer: down

   Only one branch of the if/else-if/else chain executes.

3. 3.Code Tracing 28 - If/Else Tracing: trace the branch and loop path.

   int total = 38;
   int bonus = 3;
   int penalty = 10;
   if (total % 2 == 0)
     total += bonus;
   else
     total -= penalty;
   System.out.print(total);

   • 42
   • 41
   • 31
   • 38
   Show worked solution

   Correct answer: 41

   The parity test chooses exactly one update to total.

4. 4.Code Tracing 39 - If/Else Tracing: watch the index changes.

   int value = 46;
   int x = 5;
   int y = 5;
   if (value > 30) {
     value -= x;
   } else {
     value += y;
   }
   System.out.print(value);

   • The code does not compile.
   • A runtime exception is thrown.
   • 41
   • 46
   Show worked solution

   Correct answer: 41

   The condition determines which block changes value before it is printed.

5. 5.Code Tracing 50 - If/Else Tracing: evaluate the state change step by step.

   int a = 54;
   int b = 7;
   int c = 7;
   int d = 3;
   if (a > c)
     if (b > d)
       System.out.print("X");
     else
       System.out.print("Y");
   else
     System.out.print("Z");

   • Y
   • Z
   • The code does not compile.
   • X
   Show worked solution

   Correct answer: X

   The inner if is considered only when the outer condition is true.

6. 6.What is printed by the following code segment?

   int n = 15;
   String s = "";
   if (n > 20) { s = "a"; }
   else if (n > 10) { s = "b"; }
   if (n > 5) { s += "c"; }
   else { s += "d"; }
   System.out.print(s);

   • ac
   • b
   • bc
   • bcd
   Show worked solution

   Correct answer: bc

   The chain assigns b, and the separate if that follows appends c because it is tested independently.

7. 7.What is printed by the following code segment?

   int a = 5;
   int b = 10;
   if (a > b)
   {
       System.out.print("x");
   }
   else if (a == b)
   {
       System.out.print("y");
   }
   else if (a < b)
   {
       System.out.print("z");
   }
   else
   {
       System.out.print("w");
   }

   • w
   • y
   • zw
   • z
   Show worked solution

   Correct answer: z

   The three conditions cover every case, so the trailing else is unreachable for any pair of int values.

8. 8.What is printed by the following code segment?

   int score = 85;
   String g;
   if (score >= 90) { g = "A"; }
   else { g = "B"; }
   if (score >= 80) { g = g + "+"; }
   System.out.print(g);

   • B+
   • A+
   • B
   • A
   Show worked solution

   Correct answer: B+

   The chain assigns B, and the independent if then appends the plus sign because 85 clears 80.

9. 9.What is printed by the following code segment?

   int x = 0;
   if (x > 0) { x = 1; }
   else if (x < 0) { x = -1; }
   else { x = 100; }
   if (x == 100) { x /= 4; }
   System.out.print(x);

   • 100
   • 25
   • 0
   • 1
   Show worked solution

   Correct answer: 25

   The final else runs because 0 is neither positive nor negative, and the later if then divides the updated value.

10. 10.What is printed by the following code segment?

    int a = 7;
    int b = 0;
    if (a % 2 == 1)
    {
        b += 1;
    }
    if (a % 3 == 1)
    {
        b += 2;
    }
    if (a % 5 == 2)
    {
        b += 4;
    }
    System.out.print(b);

    • 5
    • 3
    • 7
    • 1
    Show worked solution

    Correct answer: 7

    All three remainders match, so every independent if fires and the values 1, 2, and 4 accumulate.

11. 11.What is printed by the following code segment?

    String s = "hello";
    if (s.length() > 3)
    {
        if (s.charAt(0) == 'h')
        {
            s = s.substring(1);
        }
    }
    if (s.length() > 3)
    {
        s = s.substring(0, 3);
    }
    System.out.print(s);

    • hel
    • ello
    • hello
    • ell
    Show worked solution

    Correct answer: ell

    The first block drops the leading character, and the second then tests the shortened string and keeps three characters.

12. 12.What is printed by the following code segment?

    int n = 4;
    int r = 0;
    if (n > 0)
        r = 1;
        r = 2;
    System.out.print(r);

    • 2
    • 1
    • 0
    • The code does not compile.
    Show worked solution

    Correct answer: 2

    Without braces the if controls only the first statement, so the second assignment always runs regardless of the condition.

13. 13.What is printed by the following code segment?

    int a = 2;
    if (a == 1) { a = 10; }
    if (a == 2) { a = 20; }
    if (a == 20) { a = 30; }
    System.out.print(a);

    • 20
    • 30
    • 2
    • 10
    Show worked solution

    Correct answer: 30

    Each independent if tests the value as it stands at that moment, so the second change cascades into the third.

14. 14.What is printed by the following code segment?

    int t = 70;
    String s;
    if (t < 60) { s = "cold"; }
    else if (t < 80) { s = "mild"; }
    else { s = "hot"; }
    System.out.print(s.length() + s.substring(0, 1));

    • 4mild
    • 4c
    • 4m
    • 3m
    Show worked solution

    Correct answer: 4m

    The chain selects mild, whose length is 4, and the first character is appended as text.

15. 15.What is printed by the following code segment?

    int v = 3;
    int out = v > 5 ? 1 : v > 2 ? 2 : 3;
    System.out.print(out);

    • 3
    • 1
    • The code does not compile.
    • 2
    Show worked solution

    Correct answer: 2

    Conditional operators nest from the right, so the second test runs when the first fails and selects 2.