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JavaScript

Posted by Goldy Arora
Goldy Arora
646 Points

Need help with array reduce function

I have a two dimension array which includes productName, and the email of the customer who bought it. example:

[ ["productName", "CustomerEmail"], [productX, xyz@domain.com], [productY, abc@domain.com], [productX, 123@gmail.com], [productZ, 123@yahoo.com] ]

I want to output a summary which should say productX, sold 10 times productY, sold 12 times etc.

I am trying to use array reduce method which works fine as following

const count = fileArray.reduce((count, item) => {

  if (item[0] === "productX") {
    return count + 1}
    else {return count}
    },1);

console.log(`productX is sold ${count}` times)

but the data am working with has 20 products, and am sure there should be a better way instead of keep writing product name as string to compare in each iteration.

May you help?

thank you

1 Answer

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

I might do it using map, filter and a Set instead of with reduce:

[...new Set(fileArray.map(x => x[0]))].forEach(product => {
    console.log(`${product} is sold ${fileArray.filter(x => x[0] == product).length} times`);
});

Did I just do your school homework?   :see_no_evil: