Stopping and Debugging While Loops

Some loops repeat a known number of times. Others need to keep going until a changing condition says they are done. This Block focuses on the second kind: practical while loops driven by user input, sentinel values, counters, and clear exit conditions.

What you will learn:

• Use while when the number of repetitions is not known in advance
• Build input-driven and sentinel-controlled loops that stop on values such as "quit"
• Prevent infinite loops by updating the values used by the condition
• Find loops that never start and fix off-by-one boundary mistakes
• Stop loops with break and use continue without skipping essential updates
• Choose between while, for, and range() based on the task

Leave with a reliable way to design, trace, and repair loops so they stop at exactly the right moment.