Why my code not working with Basic Algorithm Scripting: Return Largest Numbers in Arrays using filter!

JavaScript
#1

Tell us what’s happening:
it successful with me using the map …look at the end of code /Done using map/
but I’m trying to solve it using filter …it didn’t work!.
why?

Your code so far


function largestOfFour(arr) {
 let y = [];let z=0;
for(let i = 0 ; i < arr.length ; i++)
 { 
     Math.max(arr[i].filter(num => {
       if(num>z){z=num}
     }))
 }  
 return z;
}

largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);
/* let x = [];
 for(let i = 0 ; i < arr.length ; i++)//
   {

   x.push(Math.max(...arr[i].map(num => num)));
   }
   return x;*/

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.135 Safari/537.36.

Challenge: Return Largest Numbers in Arrays

Link to the challenge:

#2

It’s telling you what the problem is. The first test reports:

largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]])

should return an array.

But you are not retuning an array, you’re returning a number.

If you read the instructions:

Return an array consisting of the largest number from each provided sub-array. For simplicity, the provided array will contain exactly 4 sub-arrays.

So, you should return and array of four numbers, the largest number in each subarray.

#3

this is unnecessary, you are not making any change so map is just consuming resources without adding any functionality, you could just ...arr[i]

1 Like
#4