Method

What is a method

In a word, it makes it possible to use all the processes together. I don't think this alone makes sense, so I'll actually write the code.

We want to define a method called hello to output hello.

def hello              #When defining a method, start with def and end with end
  puts "Hello"
end

hello                  #Method call

Hello#Hi defined is output at hello

Return value

The method returns the last line.

def number
  "1"
  "2"
  "3"         
end

puts number
3              #The last 3 is the output

If you enter return, the process will stop halfway.

def number
  "1"
return  "2" 
  "3"         
end

puts number
2             #2 in the middle is output

argument

Things that can pass values ​​to methods etc. This allows you to bring in values ​​outside of the defined method. (Values ​​defined outside the basically defined method cannot be used inside the method, this range is called scope)

Formal arguments that are described and used for processing when defining a method The value that is actually assigned to the formal argument when calling the method is called the actual argument.

def method name(Formal argument)
  #processing
end

Method name(Actual argument)  #Method call
def add_number(number)  #(2) Substitute the actual argument 5 for the formal argument number
  puts number + number  #③ Since the value of number is 5, 5+5 calculations are made.
end

add_number(5)  #(1) Enter a value in the actual argument and call the defined method

Multiple arguments can be specified

def method name(First argument,Second argument)
  #processing
end

Method name(First argument,Second argument)

However, the number of actual and formal arguments must always be the same.

that's all.

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