Quick start with Go

1. Select File | New | New Project.

   Alternatively, click New Project in the Welcome to IntelliJ IDEA dialog.

2. In the New Project dialog, select Go modules from the list of available project types.

   Ensure that Go is selected as the project language in the Language list.

3. In the GOROOT field, specify the location of your Go installation. IntelliJ IDEA usually detects this location automatically.

   To change or install a new Go SDK version, click Add SDK () and choose one of the following options:

   • Local: to use an existing SDK from your local system.

   • Download: to download a Go SDK version from the official repository.

4. Click Create to create the project.

   

1. To create a Go file, use one of the following options:

   • In the Project tool window, right-click the parent folder of your project and select New | Go FileGo File.

   • Click the parent folder of your project, press AltInsert, and select Go File.

   • Click the parent folder of your project, then go to File | New | Go File.

2. In the New Go File dialog, enter a file name and choose the file type:

   • Empty file — creates an empty Go file.

   • Simple application — creates a Go file with a predefined main function.

   

Refactoring is a process of improving your source code without creating a new functionality. Refactoring helps you keep your code solid , dry, and easy to maintain.

IntelliJ IDEA provides the following refactoring options:

• Change signature: rename methods or functions, add, remove, or reorder parameters, and assign default values to new non-variadic parameters.

• Extract refactorings: extract code fragments into constants, variables, methods, or interfaces to improve clarity and reusability.

• Inline refactoring: move the contents of a method or variable directly into the place where it is used. This is the opposite of Extract refactoring.

• Copy refactoring: copy a file, directory, or package to another location.

• Move refactoring: move functions, types, or other code elements to different packages or files to improve project structure.

IntelliJ IDEA provides two types of code completion:

• Basic code completion CtrlSpace helps complete names of types, interfaces, methods, and keywords within the current scope. Suggestions appear automatically as you type.

• Smart code completion CtrlShiftSpace filters the list to show only values suitable for the current context.

  The following animation demonstrates the difference between basic and smart type-matching completions. Notice the number of suggestions offered for each type:

IntelliJ IDEA provides multiple ways to generate common code constructs and recurring elements, which helps you increase productivity. These can be either file templates used when creating a new file, custom or predefined live templates that are applied differently based on the context, various wrappers, or automatic pairing of characters.

• You can generate getters, setters, constructors, missing methods, and test files.

Use live templates to insert common constructs into your code, such as loops, conditions, declarations, or print statements.

• To see the list of live templates, press CtrlAlt0S and go to Editor | Live Templates.

  The following animation shows how to create a Hello World program using a live template:

In IntelliJ IDEA, there is a set of code inspections that detect and correct abnormal code in your project before you compile it. The IDE can find and highlight various problems, locate dead code, find probable bugs, spelling problems, and improve the overall code structure.

Inspections can scan your code in all project files or only in specific scopes (for example, only in production code or in modified files).

Every inspection has a severity level — the extent to which a problem can affect your code. Severities are highlighted differently in the editor so that you can quickly distinguish between critical problems and less important things. IntelliJ IDEA comes with a set of predefined severity levels and enables you to create your own.

• To view and configure inspections, press CtrlAlt0S and navigate to Editor | Inspections. You can enable or disable inspections and change their severity levels.

  For example, the Unreachable code inspection detects unreachable code.

  

As you work in the editor, IntelliJ IDEA analyzes your code and searches for ways to optimize it. Intention actions cover a wide range of situations from errors and warnings to optimization suggestions.

As soon as the IDE finds a way to improve your code, it displays a yellow bulb icon in the editor next to the current line. By clicking this icon, you can view the intention actions available in the current context.

To see the list of available intention actions, press CtrlAlt0S and navigate to Editor | Intentions.

1. Click the light bulb icon or press AltEnter to open the list of suggestions.

2. Select an action from the list and press Enter.

   For example, you can use an intention action to inject another language into your code:

   

• To run your application, press ShiftF10, or click the Run Application icon in the gutter and select Run <application_name>.

  

Debugging begins with placing breakpoints, which suspend program execution so you can inspect program data. To set a breakpoint, click the line number in the gutter where you want execution to pause.

• To debug your application, press ShiftF9, or click the Run Application icon in the gutter and select Debug <application_name>. Then, step through the execution using the options in the Run menu or the Debug tool window.

  For more information, refer to Debugging.