DRAFT
ForVariableScopeBeyondLoop
Misconception:
The scope of a variable defined in a for loop header extends beyond that loop.
Incorrect
The scope of variables declared in a for loop header extends beyond the loop
Correct
The scope of variables declared in a for loop header is limited to the loop
CorrectionHere is what's right.
Here is what's right.
A variable declared in the for loop header is only visible within the loop header and body, but not outside the loop. The scope of that variable is the loop.
for (int i=0; i<n; i++) {
// variable i is in scope here
}
// variable i is NOT in scope hereSymptomsHow do you know your students might have this misconception?
How do you know your students might have this misconception?
This misconception shows up when students need to write multiple loops in a method, like this:
for (int i=0; i<n; i++) {
// work with i
}
for (int j=0; j<n; j++) {
// work with j
}Students with that misconception use a different variable name for the second loop (even if the purpose of that variable is the same).