The second iterator we’re going to cover is .map()
. When .map()
is called on an array, it takes an argument of a callback function and returns a new array! Take a look at an example of calling .map()
:
const numbers = [1, 2, 3, 4, 5]; const bigNumbers = numbers.map(number => { return number * 10; });
.map()
works in a similar manner to .forEach()
— the major difference is that .map()
returns a new array.
In the example above:
numbers
is an array of numbers.bigNumbers
will store the return value of calling.map()
onnumbers
.numbers.map
will iterate through each element in thenumbers
array and pass the element into the callback function.return number * 10
is the code we wish to execute upon each element in the array. This will save each value from thenumbers
array, multiplied by10
, to a new array.
If we take a look at numbers
and bigNumbers
:
console.log(numbers); // Output: [1, 2, 3, 4, 5] console.log(bigNumbers); // Output: [10, 20, 30, 40, 50]
Notice that the elements in numbers
were not altered and bigNumbers
is a new array.
Instructions
Add your code under the animals
array and before the line console.log(secretMessage.join(''));
Use .map()
to create a new array that contains the first character of each string in the animals
array. Save the new array to a const
variable named secretMessage
.
Use .map()
to divide all the numbers in bigNumbers
by 100
. Save the returned values to a variable declared with const
called smallNumbers
.