# Iterate Through All an Array&#x27;s Items Using For Loops instructions

Iterate Through All an Array&#x27;s Items Using For Loops instructions
0

#1

Tell us what’s happening:

Hey i just do not understand the instructions in this challenge.

``````
function filteredArray(arr, elem) {
let newArr = [];
// change code below this line
for(let i =0;i<arr.length;i++){
if(arr[i].indexOf(elem) === -1){
newArr.push(arr[i]);
}
}
// change code above this line
return newArr;
}

// change code here to test different cases:
console.log(filteredArray([[3, 2, 3], [1, 6, 3], [3, 13, 26], [19, 3, 9]], 3));
``````

User Agent is: `Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36`.

#2

What type will `arr[i][j]` be? Will it be an array?

#3

your code works perfectly but you say you don’t understand?
Can you tell us what exactly you need clarification on?

#4

Hey @hbar1st i actually copied the solution code.
The thing that i fo not get is arr.indexOf(elem)

#5

No it will not be i guess

#6

arr is an array
indexOf is a function that acts on an array

• it takes a value parameter to look for in the array and returns the index of that value if found (or -1 if not)

#7

I just had the issue cause of nested arrays .
Now, i have got it after some reading.
Thanks.

#8
``````function filteredArray(arr, elem) {
let newArr = [];
// change code below this line
for(let i =0;i<arr.length;i++){
if(arr[i].indexOf(elem) === -1){
newArr.push(arr[i]);
}
}
// change code above this line
return newArr;
}

// change code here to test different cases:
console.log(filteredArray([[3, 2, 3], [1, 6, 3], [3, 13, 26], [19, 3, 9]], 3));
``````

Why does this console log an empty array for me? Anyone?

#9

Because that is what the code should be doing to pass the challenge. The instructions state:

Modify the function, using a for loop, to return a filtered version of the passed array such that any array nested within arr containing elem has been removed.

Since 3 is contained in each of the sub-arrays, so they all get removed from the final array (newArr). Since newArr starts as an empty array, it remains as an empty array, because no sub-arrays were pushed.

#10

Welp. I misunderstood that for days. Thank you. @RandellDawson