IDEs

This is a printer-friendly version. It omits exercises, optional topics (i.e., four-star topics), and other extra content such as learning outcomes.

Introduction

What

Professional software engineers often write code using Integrated Development Environments (IDEs). IDEs support all development-related work within the same tool.

An IDE generally consists of:

  • A source code editor that includes features such as syntax coloring, auto-completion, easy code navigation, error highlighting, and code-snippet generation.
  • A compiler and/or an interpreter (together with other build automation support) that facilitates the compilation/linking/running/deployment of a program.
  • A debugger that allows the developer to execute the program one step at a time to observe the run-time behavior in order to locate bugs.
  • Other tools that aid various aspects of coding e.g. support for automated testing, drag-and-drop construction of UI components, version management support, simulation of the target runtime platform, and modeling support.

Examples of popular IDEs:

  • Java: Eclipse, Intellij IDEA, NetBeans
  • C#, C++: Visual Studio
  • Swift: XCode
  • Python: PyCharm

Some Web-based IDEs have appeared in recent times too e.g., Amazon's Cloud9 IDE.

Some experienced developers, in particular those with a UNIX background, prefer lightweight yet powerful text editors with scripting capabilities (e.g. Emacs) over heavier IDEs.

Debugging

What

Debugging is the process of discovering defects in the program. Here are some approaches to debugging:

  • Bad -- By inserting temporary print statements: This is an ad-hoc approach in which print statements are inserted in the program to print information relevant to debugging, such as variable values. e.g. Exiting process() method, x is 5.347. This approach is not recommended due to these reasons.

    • Incurs extra effort when inserting and removing the print statements.
    • Unnecessary program modifications increases the risk of introducing errors into the program.
    • These print statements, if not promptly removed, may even appear unexpectedly in the production version.

  • Bad -- By manually tracing through the code: Otherwise known as ‘eye-balling’, this approach doesn't have the cons of the previous approach, but it too is not recommended (other than as a 'quick try') due to these reasons:

    • It is difficult, time consuming, and error-prone technique.
    • If you didn't spot the error while writing code, you might not spot the error when reading code too.

  • Good -- Using a debugger: A debugger tool allows you to pause the execution, then step through one statement at a time while examining the internal state if necessary. Most IDEs come with an inbuilt debugger. This is the recommended approach for debugging.