Ampersand Argument in Ruby with examples
In Ruby, the ampersand (&) is used to convert a block into a proc (short for "procedure"), which is a type of callable object that can be passed as an argument to a method. This allows developers to pass blocks of code as arguments to methods, and to execute the code at a later time.
Here is an example of using the ampersand to convert a block into a proc:
# Define a method that takes a proc as an argument
def my_method(proc)
# Execute the proc
proc.call
end
# Define a block of code
my_block = proc { puts "Hello, world!" }
# Pass the block to the method as a proc
my_method(my_block)
In this example, the my_method
method takes a proc as an argument, and uses the call
method to execute the proc. The my_block
proc is defined using the proc
keyword, and is passed as an argument to the my_method
method. When the my_method
method is called, it executes the my_block
proc, which prints "Hello, world!" to the console.
Here is another example of using the ampersand to convert a block into a proc:
# Define a method that takes a proc as an argument
def my_method(proc)
# Execute the proc
proc.call
end
# Pass the block directly to the method, using the ampersand to convert it to a proc
my_method(&proc { puts "Hello, world!" })
In this example, the my_method
method is called with a block of code as an argument, using the ampersand to convert the block into a proc. When the my_method
method is called, it executes the block, which prints "Hello, world!" to the console.
Here is another example of using the ampersand to convert a block into a proc, and to pass it to a method as an argument:
# Define a method that takes a proc as an argument
def my_method(proc)
# Execute the proc
proc.call
end
# Define an array of numbers
numbers = [1, 2, 3, 4, 5]
# Pass the block directly to the method, using the ampersand to convert it to a proc
numbers.each(&proc { |n| puts n })
In this example, the my_method
method is called with a block of code as an argument, using the ampersand to convert the block into a proc. The each
method is called on the numbers
array, and the proc is passed as an argument to the each
method. When the each
method is called, it iterates over the numbers
array and executes the proc for each element, which prints the numbers to the console.
Overall, the ampersand is a useful operator in Ruby that allows developers to convert blocks of code into procs, and to pass these procs as arguments to methods. By using the ampersand, developers can pass blocks of code as arguments to methods, and execute the code at a later time.