Help - Slice and Splice

JavaScript
#1

Hi,

I didn’t know how to use splice() so I used other ways to solve the problem.
what did I do wrong here?


function frankenSplice(arr1, arr2, n) {
let result = [];
let array1 = arr1.toString();
let array2 = arr2.toString();

for (let i = 0; i<array1.length; i++){
for (let j = 0; j<array2.length; j++){
  if (array1[j] == n){
     return result += array2[j] + array1 + array2.slice(1);
      }
   }
}
   return result;
}

console.log(frankenSplice([1, 2, 3], [4, 5], 1));

It should return [4, 1, 2, 3, 5], however my code returns [41,2,3,5].
I wanted to do arr1.split() so there will have a comma between 4 and 1, but it says arr1.split is not a function.

I feel like I am so close to the answer but also feel that my logic could be totally wrong.

Please help, thank you!

Link to the challenge: https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/basic-algorithm-scripting/slice-and-splice

#2

You should create a separate copy of arr2, and use a for loop to insert values of arr1 in the arr2 clone with splice method.

#3

Hi could you please explain it more?

#4

So create a separate copy of arr2 using the slice method because the challenge does not want you to mutate it.

Now using a for loop, insert values of arr1 into arr2 with splice method, starting at n.

Increment n after each splice to put it in the corresponding index.
Let me know if you still need help.

#5

Another way to copy the array is to use the spread operator. It was one of the previous exercises under Basic Data Structures: Copy an Array with the Spread Operator leading up the point of this current one.

#6

yes, I just learned how to use splice() and spread operator together to solve this problem, it’s much simpler.

#7

what do you think is the value of array1 here?

you can look at what happens with a tool like this: http://pythontutor.com/javascript.html#mode=edit

#8

let array1 = arr1.toString(); // returns 1,2,3

#9

and it’s a string, then you are looping through a string, until a character in the string is equal to n

it’s not exactly what you want to get

try looking at your code with that tool

#10

Thank you! I will take a look with that tool

#11