Question 1

Are there exceptions where modifying the counter is okay?

Accepted Answer

In some string parsing algorithms, manually advancing the pointer is common, but it must be done with extreme care and clear documentation.

Question 2

Is it illegal to modify a for loop counter inside the block?

Accepted Answer

No, the compiler allows it. However, it is considered bad practice because it makes the loop's behavior unpredictable and hard to debug.

Question 3

Why does my loop skip elements unexpectedly?

Accepted Answer

If you increment the counter manually inside the loop, the loop's natural update step will increment it again, causing it to skip an element.

Question 4

What loop should I use if I need to skip elements dynamically?

Accepted Answer

Use a while loop. It places the responsibility of updating the counter entirely inside the block, making dynamic jumps explicit and clear.

Are there exceptions where modifying the counter is okay?

More FAQs in The Danger of Modifying Loop Counters Manually