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JavaScript JavaScript Array Iteration Methods Combining Array Methods Array Flattening

Posted by Zach Freitag
Zach Freitag
20,341 Points

Using reduce method, flatten the customerNames array of arrays.

Using reduce method, flatten the customerNames array of arrays. In other words, take all the names from each array inside customerNames and place them in one big array. Store the flattened array in the flattenedCustomerNames variable. You can use the array in the comments below for reference.

const customerNames = [
    [ "John", "Sandy", "Tyrone", "Elizabeth", "Penny" ],
    [ "Barry", "Wanda", "Jamal", "Hayden" ],
    [ "Portia", "Pam", "Philip" ]
];
let flattenedCustomerNames;

// flattenedCustomerNames should be: ["John", "Sandy", "Tyrone", "Elizabeth", "Penny", "Barry", "Wanda", "Jamal", "Hayden", "Portia", "Pam", "Philip"]
// Write your code below

4 Answers

Zach Freitag
Zach Freitag
20,341 Points

This worked!

flattenedCustomerNames = customerNames.reduce((arr, innerNames) => [ ...arr, ...innerNames], []);

console.log(flattenedCustomerNames);

Cheers!

Dan Otieno
Dan Otieno
23,495 Points
Dan Otieno
Dan Otieno
23,495 Points

This on the console: const customerNames = [ [ "John", "Sandy", "Tyrone", "Elizabeth", "Penny" ], [ "Barry", "Wanda", "Jamal", "Hayden" ], [ "Portia", "Pam", "Philip" ] ]; let flattenedCustomerNames; flattenedCustomerNames = customerNames.reduce((arr, innerNames) => [ ...arr, ...innerNames], []); (12) ["John", "Sandy", "Tyrone", "Elizabeth", "Penny", "Barry", "Wanda", "Jamal", "Hayden", "Portia", "Pam", "Philip"]

Noah Yasskin
Noah Yasskin
23,947 Points
Noah Yasskin
Noah Yasskin
23,947 Points

with syntax highlighting:

flattenedCustomerNames = customerNames.reduce((arr, innerNames) => [...arr, ...innerNames], []);
Theo Lufkin
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Theo Lufkin
Web Development Techdegree Graduate 15,577 Points
Theo Lufkin
.a{fill-rule:evenodd;}techdegree seal-36
Theo Lufkin
Web Development Techdegree Graduate 15,577 Points

Why does 'innerNames' work, and not come up as 'undefined' like when I try to use a different name. 'innerNames' is also not defined anywhere in the code.