Скачать или смотреть How to Assign a Function to a Variable in Go Without Executing It

Learn how to assign functions to variables in Go without causing them to execute immediately. Our guide simplifies the process for you!
---
This video is based on the question https://stackoverflow.com/q/64289712/ asked by the user 'C0lin' ( https://stackoverflow.com/u/13188049/ ) and on the answer https://stackoverflow.com/a/64291710/ provided by the user 'kozmo' ( https://stackoverflow.com/u/8030651/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: How can I assign a function to a variable without executing it?

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Understanding Function Assignment in Go

In Go, functions are first-class citizens, meaning they can be assigned to variables and passed around just like other data types. However, sometimes you may want to assign a function to a variable without executing it right away. This is a common concern when working with maps in Go. In this guide, we will explore how to assign a function to a variable without executing it, clarifying the process with code examples and explanations.

The Problem: Function Execution on Assignment

When you're assigning a function to a map key in Go, you might run into the issue of the function being executed immediately. Let's take a look at an example that illustrates this problem:

[[See Video to Reveal this Text or Code Snippet]]

In this code snippet, the function RemoveIndex is assigned to the key "removeIndex" in map a. However, it executes immediately, returning a result instead of just being assigned for later use.

The Solution: Correctly Assigning the Function

To assign a function to a map entry without executing it, you need to reference the function directly rather than calling it. Here’s how you can do it effectively:

Step-by-Step Breakdown

Define the Function: Make sure your function is defined properly so that it can be assigned without arguments being passed at the moment of assignment.

[[See Video to Reveal this Text or Code Snippet]]

Assign the Function by Reference: When assigning the function to the map, make sure to omit the parentheses (), which would execute the function. Instead, reference the function itself.

[[See Video to Reveal this Text or Code Snippet]]

Retrieve and Execute the Function Later: To execute the function later, retrieve it from the map and invoke it as you normally would.

[[See Video to Reveal this Text or Code Snippet]]

Complete Example Code

Here's the complete code, demonstrating these steps:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

In Go, assigning a function to a variable or map without executing it is straightforward once you understand the required syntax. Instead of calling the function immediately, simply reference it by its name, and you can execute it later when needed. This allows for much more flexibility in program design, enabling you to create dynamic and responsive applications.

Whether you're managing functions in maps or developing more complex systems, mastering function assignment is a crucial skill in Go. Happy coding!