- Practice iterating over an array using the
.eachmethod. - Practice operating on each element of an array.
You will build a method, square_array, that squares each element in an array of numbers and returns a new array of these squared numbers. Use an iterator and implement your own logic, don't use any built-in array methods other than .each (e.g. .collect, .inject).
A couple of questions that you can ask yourself are:
- What is the return value of calling
.eachon an array? - How can I operate on each element of an array and also collect or store those elements?
- How can I square a number? Hint: There is more than one way to do it! You can use the exponent operator (Google Ruby's exponent operator to learn how it works) or you can use simple math. Refer back to the earlier lesson on math if you need a refresher.
Once you have the tests passing, see if you can implement this with a higher level iterator such as .collect.
numbers = [1,2,3]
square_array(numbers)
# => [1,4,9])
new_numbers = [9,10,16,25]
square_array(new_numbers)
# => [81,100,256,625]