Scope CS Thinking Example 3

Follow the full solution, then compare it with the other examples linked below.

Example 3

medium
What is the output? SET y = 100. FUNCTION test(): OUTPUT y. test(). Will this work, or will there be an error?

Solution

  1. 1
    Step 1: Most languages allow functions to read global variables (though not modify them without special syntax).
  2. 2
    Step 2: The function reads y = 100. Output: 100. No error.

Answer

Output: 100. The function can read the global variable y.
Reading global variables from functions usually works, but writing to them requires explicit declaration (e.g., `global y` in Python). The distinction between reading and writing globals is language-specific.

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 hard

Explain why using global variables inside functions is generally discouraged.

Example 4 medium

What is the output? Explain any errors. SET count = 0 FUNCTION increment() SET count = count + 1

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