Answer source: Dzone
If you believe code reviewing isn’t required as long as you are testing, then the below-mentioned benefits may sway you towards thinking differently.
1. Early Bug Detection: When bugs are detected at a very early stage in the development phase, it reduces a lot of time during the testing phase. The overall process becomes a lot less expensive. Automation testing reduces the testing effort and time spent; still, there is no better gift than the human nature of detecting and correcting mistakes committed by others.
2. Mentoring Juniors: When a freshman joins a project, seniors may not have much time to mentor or guide the junior about the coding practices or train them about how they do their job. The ideal solution in that scenario for a senior developer is to spend at least 20-30 minutes in reviewing the code written by the junior. Regular feedback will allow the new developer to develop his/her skill in coding.
3. Age of Agile: Nowadays most organizations follow Agile methodology and require to deliver quality work in time. A code review will enable the organization to develop a quality prototype, free from defects, and developed following the standard protocols.
4. Team Cohesion: Frequent review discussion brings the team closer, makes them aware of each other’s strengths and weaknesses, and saves them from getting stuck in an isolated environment.
5. Compliance to Standards: In the Agile age, the client often requires us to abide by a certain coding standard. However, fresher developers are not often aware of industry-standard coding. Frequent reviews help to ensure that the code abides by the rules and standards that have been set by the stakeholders.