Scope CS Thinking Example 4
Follow the full solution, then compare it with the other examples linked below.
Example 4
mediumWhat is the output? Explain any errors.
SET count = 0
FUNCTION increment()
SET count = count + 1
SET bonus = 10
END FUNCTION
increment()
OUTPUT count
OUTPUT bonus
Solution
- 1 Step 1: count is a global variable, set to 0.
- 2 Step 2: increment() runs. If the language allows modifying globals, count becomes 1. bonus is created as a local variable inside increment, set to 10.
- 3 Step 3: OUTPUT count → outputs 1 (global was modified).
- 4 Step 4: OUTPUT bonus → ERROR. bonus was local to increment() and does not exist outside it.
Answer
Output: 1, then an error on OUTPUT bonus. Local variables created inside a function are not accessible outside it — they go out of scope when the function ends.
Scope rules protect functions from interfering with each other. A variable created inside a function is local by default and disappears when the function returns. Accessing it outside causes a 'not defined' error.
About Scope
The region of a program where a variable is accessible. Variables defined inside a function have local scope and exist only within that function. Variables defined outside all functions have global scope and are accessible from anywhere in the program.
Learn more about Scope →More Scope Examples
Example 1 medium
What is the output? SET x = 10. FUNCTION addFive(): SET x = 5. RETURN x + 5. OUTPUT addFive(). OUTPU
Example 2 hardExplain why using global variables inside functions is generally discouraged.
Example 3 mediumWhat is the output? SET y = 100. FUNCTION test(): OUTPUT y. test(). Will this work, or will there be