About Ruby arrays


Arrays can hold multiple values. Variables can only hold one value.

Arrays can be used by enclosing multiple values in parentheses [], such as array name = ["value 1 "," value 2 "," value 3 "]. Each value is separated by a comma (,).

Benefits of using arrays

The method of preparing an array and storing the values has the following advantages.

--No need to define variables every time --The code is easier to read --The amount of code written is reduced

Not only can an array hold multiple values, but you can also assign those values to variables and output their contents.


names = ["sawamura", "yamada", "tanaka"]
puts names
#=> sawamura
#   yamada
#   tanaka

As shown above, the values stored in the array are displayed in order.

Get elements of an array

The values stored in the array are numbered in order. This assigned number is called the ** index number **, and the value contained in the array is called the ** element **.

To retrieve a specific element, use the following syntax.

Array name [index number] (Example)

names = ["sawamura", "yamada", "tanaka"]
puts names[0]
#=> sawamura

Add elements to the array

If you want to add an element to the array, you can add it with <<.

names = ["sawamura", "yamada", "tanaka"]
names << "sato"
puts names
#=> sawamura
#   yamada
#   tanaka
#   sato

push method

The push method, like the << method, adds a new element to the end of the array. The difference is that you can add only one element to the array with the << method, but you can add multiple elements at once with push.


names = ["sawamura", "yamada", "tanaka"]
puts names
#=> sawamura
#   yamada
#   tanaka
#   sato
#   wakabayashi

Remove elements from array

shift method

The shift method is a method that deletes the first element of the array.


names = ["sawamura", "yamada", "tanaka"]
puts names
#=> yamada
#   tanaka

#The index has also been updated
puts names[0]
#=> yamada


--Each array has an index that represents the element number --Use a form like names [0] to specify the index of the array and retrieve the element. --If you want to add an element to the array, use << to add it

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