Functions
Ruby Procs
Using Procs
Ruby Procs create callable objects with lambda-like behavior.
What is a Proc in Ruby?
In Ruby, a Proc is an object that encapsulates a block of code, which can be stored in a variable, passed to a method, or called at a later point in your program. Procs provide a way to capture code and its surrounding context to be executed at a later time.
Procs are similar to lambdas in Ruby but with some differences in behavior, particularly in terms of return handling and argument checking.
Creating a Proc
To create a Proc, you can use the Proc.new method or the proc method. Here is an example of how to create a Proc:
Calling a Proc
Once a Proc is created, you can call it using the call method. Below is an example of calling a Proc:
Differences Between Procs and Lambdas
While Procs and lambdas are similar, there are key differences:
- Return Behavior: In a lambda, the return keyword exits the lambda itself, whereas in a Proc, it will exit the method that contains the Proc.
- Argument Checking: Lambdas check the number of arguments passed, while Procs do not enforce this.
Here is an example illustrating these differences:
Using Procs as Method Arguments
Procs can be passed as arguments to methods, allowing you to provide custom behavior. Here's how:
Conclusion
Ruby Procs are powerful tools for managing code blocks and creating flexible, reusable code. They provide a mechanism for encapsulating code that can be executed at a later time. Understanding the differences between Procs and lambdas will help you choose the right tool for your task.
In the next section, we will explore Ruby Lambdas and how they differ from Procs.
