Would someone help me?(Falsy Bouncer)

Curriculum Help
1

Tell us what’s happening:
Describe your issue in detail here.

i use the follow code to test the result.

The test result is [ false, 9 ] which eliminate [7, “ate”].

I am not sure which part is wrong. Can anyone help me?

  **Your code so far**



function bouncer(arr) {
for(let i=0;i<arr.length;i++){
  let n=i+1;
  if(arr[i]===false||arr[i]===null||arr[i]===0||arr[i]=== ""||arr[i]===undefined||arr[i]===NaN){
    arr.splice(0,n);
  }
}
return arr;
}

console.log(bouncer([7, "ate", "", false, 9]));

  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36

Challenge: Falsy Bouncer

Link to the challenge:

2

You have two problems

  1. You can’t check for all falsy values like this. arr[i] === NaN will never work because NaN === NaN is false. Luckily, you don’t need to do this, because the entire idea of falsy and truthy is that falsy values act like false when treated as a boolean value and truthy values act like true when treated as a boolean value.

  2. Modifying an array as you loop over it will make a big mess. In general, you should never splice out parts of an array as you iterate over the array.

3

I think you are making this a little too complicated. As @JeremyLT said, there is a much easier way to check for “falsy” values in JS. If you aren’t sure about that then a little googling will probably give you what you need.

I can see why you are modifying the original array passed into the function. I don’t think the instructions are quite clear enough. They should say, “Return a new array with all ‘falsy’ values removed from the array passed in”. It also doesn’t help that the default code has

return arr;

in the body of the function.

4

Tell us what’s happening:
Describe your issue in detail here.

i use the follow code to test the result.

The result shall be but now appears [ NaN ].

I have added the [ NaN ] scenario in the if statement.
Why still appear?

  **Your code so far**



function bouncer(arr) {
let newarr=[];
for(let i=0;i<arr.length;i++){
  if(arr[i]!==NaN&&arr[i]!==null&&arr[i]!==0&&arr[i]!== ""&&arr[i]!==undefined&&arr[i]!==false){
    newarr.push(arr[i]);
  }
}
return newarr;
}

console.log(bouncer([false, null, 0, NaN, undefined, ""]));

  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36

Challenge: Falsy Bouncer

Link to the challenge:

5

This isn’t any better. You cannot directly compare against some falsy values.

You need to use the idea behind falsy and truthy values.

What happens if you run this code:

if (5)
  console.log("5 is truthy");
else
  console.log("5 is falsy");

if (0)
  console.log("0 is truthy");
else
  console.log("0 is falsy");
6

Hi @alexllooyyoo !

Welcome to the forum!

I think reviewing the definition for if statements will help you.

MDN Docs:
The if statement executes a statement if a specified condition is truthy

Hopefully that helps you simplify this if statement.