How to change a string in an array to a number in Ruby

array = ["1", "2", "3", "4", "5"]

I will write a method to change the character string of the array to a number when there is a numerical value in the character string in the array like.

for statement method

array = ["1", "2", "3", "4", "5"]

intArray = []
for n in array
  intArray.push(n.to_i)
end

# intArray => [1, 2, 3, 4, 5]

Create an array ʻintArray = [] that is different from ʻarray. The process of getting the value of ʻarray with n, changing the character string to a numerical value with to_i, and assigning the value to ʻintArray with push is repeated.

map method method

array = ["1", "2", "3", "4", "5"]

intArray = array.map{ |n| n.to_i }

# intArray => [1, 2, 3, 4, 5]

Or

array = ["1", "2", "3", "4", "5"]

intArray = array.map(&:to_i)

# intArray => [1, 2, 3, 4, 5]

The map method iteratively processes the array ʻarray, assigns the value to the variable n, and executes the process n.to_i or &: to_i as the process you want to execute. Substitute the executed process into ʻintArray. In this case, it is not necessary to define in advance like ʻintArray = [] `.

You can also use map!, in this case

array = ["1", "2", "3", "4", "5"]

array.map!{ |n| n.to_i }

# array => [1, 2, 3, 4, 5]

You can rewrite the array of ʻarray` like this.

Reference site

https://techacademy.jp/magazine/19868 https://uxmilk.jp/21695

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