Intermediate Algorithm Scripting - Drop it

JavaScript
1

Why does this not work?

Your code so far

function dropElements(arr, func) { 
  for (let i=0;i<=arr.length;i++)
  if(func(arr)=== true){
  return arr
  } else {
  arr.splice(arr[i]) 
  dropElements;
}
}


dropElements([1, 2, 3], function(n) {return n < 3; });

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Challenge: Intermediate Algorithm Scripting - Drop it

Link to the challenge:

2

Changing the array as you iterate over it produces confusing results. You shouldn’t do that.

Also, I don’t understand why you have that line with dropElements? I’m not sure what its doing?

I also recommend using more standard formatting so it’s easier to understand the logical flow of your code.

function dropElements(arr, func) { 
  for (let i = 0; i <= arr.length; i++) {
    if (func(arr) === true) {
      return arr;
    } else {
      arr.splice(arr[i]);
      dropElements;
    }
  }
}
3

the drop elements line is meant to be an example of recursion, so if it doesnt work then it goes back and tries the function again.
I don’t really understand what you mean by not changing the array as iitterate over it

4

But you aren’t calling the function, so that line doesn’t do anything.

Look at this code:

const testArray = [1, 2, 3, 4, 5];

for (let i = 0; i < testArray.length; i++) {
  console.log("i:", i);
  console.log("array before splice:", testArray);
  testArray.splice(i);
  console.log("array after splice:", testArray);
}

What do you see in the console when you run this code?

Or this version:

const testArray = [1, 2, 3, 4, 5];

for (let i = 0; i < testArray.length; i++) {
  console.log("i:", i);
  console.log("array before splice:", testArray);
  testArray.splice(i, 1);
  console.log("array after splice:", testArray);
}

I’d just skip splice altogether here.

5

ok that makes more sense

1 Like