--- description: Loop Testing completely focus on the validity of the loop constructs. It is one of the part of Control Structure Testing (path testing, data validation testing, condition testing). In this tutorial, y title: What is Loop Testing? Methodology, Example image: https://www.guru99.com/images/4-2016/040516_0519_LoopTesting1.png --- [Skip to content](#main) ## What is Loop Testing? Loop Testing is defined as a software testing type, that completely focuses on the validity of the loop constructs. It is one of the parts of Control Structure Testing (path testing, data validation testing, condition testing). Loop testing is a [White box testing](https://www.guru99.com/white-box-testing.html). This technique is used to test loops in the program. [![Loop Testing](https://www.guru99.com/images/4-2016/040516_0519_LoopTesting1.png)](https://www.guru99.com/images/4-2016/040516%5F0519%5FLoopTesting1.png) ## Types of loop Tested Examples of types of loop tested are, * Simple loop * Nested loop * Concatenated loop * Unstructured loop ## Why do Loop Testing? Loop Testing is done for the following reasons * Testing can fix the loop repetition issues * Loops testing can reveal performance/capacity bottlenecks * By testing loops, the uninitialized variables in the loop can be determined * It helps to identify loops initialization problems. ## How to do Loop Testing: Complete Methodology While testing loop, it has to be checked at three different levels: * When loop is entered * During its execution and * When the loop is left The testing strategy for all these loops is as follow **Simple loop** A simple loop is tested in the following way: [![Simple loop](https://www.guru99.com/images/4-2016/040516_0519_LoopTesting2.png)](https://www.guru99.com/images/4-2016/040516%5F0519%5FLoopTesting2.png) 1. Skip the entire loop 2. Make 1 passes through the loop 3. Make 2 passes through the loop 4. Make a passes through the loop where a