Trying to use forEach to count occurrences in 2D array

Question

I'm trying to get familiar with arrow functions and in this case the ability to count the number of occurrences of a string within a 2D array. This is what I have so far:

GOAL Count the number of occurrences of 'cat' in a 2D array

Array

var arr = [ ['mammal','dog','fur'], ['mammal','cat','fur'], ['mammal','cat','fur'], ['fish','trout','scales'] ];

Current code using forEach

  var count = arr.map(outer => outer.forEach(str => {
    if(str == 'cat') {
    count + 1;}
     }));

  return console.log(count.length);

ACTUAL RESULT

Info 4

DESIRED RESULT

Info 2

As I mentioned, I'm still new to custom functions so any help would be sincerely appreciated.

Answer 1

Here are some.. more efficient solutions.

.map() isn't necessarily the strongest Array Method to use here, as we don't need to clone and modify the original array as we iterate through the data. We're just looking counting occurances.

---

Using .reduce():

const count = arr.reduce((acc, row) => {

    row.forEach((item) => {
      if (item === `cat`) acc++
    })

    return acc

}, 0)

• Array.reduce()

---

Using .flatMap() and .filter():

const count = arr.flatMap((row) => row).filter((item) => item === `cat`).length

• Array.flatMap()
• Array.filter()

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Learn More:

Array Methods