# 15: Test Before Loops

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• 15.1: Increment and Decrement Operators
The idea of increment or decrement is to either add or subtract 1 from a variable that is usually acting as a flag.
• 15.2: While Loop
The concept of iteration is connected to possibly wanting to repeat an action. Like all control structures we ask a question to control the execution of the loop. The term loop comes from the circular looping motion that occurs when using flowcharting.
• 15.3: Practice 14 Test Before Loops

This page titled 15: Test Before Loops is shared under a CC BY license and was authored, remixed, and/or curated by Kenneth Leroy Busbee (OpenStax CNX) .