선생님 질문이요..!
최근본상품 만들려고 코드를 짰는데요...

let cp = localStorage.getItem('cp');
let currentlyProduct = JSON.parse(cp);
let cp = localStorage.getItem('cp');
let currentlyProduct = JSON.parse(cp); // ["0"]
if(currentlyProduct == null) {
currentlyProduct = [];
currentlyProduct.push(id);
}
else{
let fi = currentlyProduct.findIndex((x)=>x==id);
if(fi == null){
currentlyProduct.push(id);
}
else{
currentlyProduct.splice(fi,1);
currentlyProduct.unshift(id);
}
}
var jCp = JSON.stringify(currentlyProduct);
localStorage.setItem('cp',JSON.stringify(jCp));

이런 오류가 나는데, 왜그러는지 잘 모르겠습니다..!