如何使用 javascript 替换 localstorage 中的值？

Question

如果本地存储中存在该值，我想替换它。当我尝试这样做时，现有值仍在插入。

  addEntry = (e,id) => {
  
  e.preventDefault()

  let product_list = []
  let productCost = document.getElementById('projectcost').value;
  let productQty = document.getElementById('productQty'+id).value;
  let productId = id;

  if(localStorage.getItem('myItems')){
  
    product_list = JSON.parse(localStorage.getItem('myItems'))
    product_list.push({productId,productCost,productQty})
    localStorage.setItem('myItems',JSON.stringify(product_list))

   }else{
   
    product_list.push({productId,productCost,productQty})
    localStorage.setItem('myItems',JSON.stringify([{productId,productCost,productQty}]))
   }
}

输出

[{"productId":43,"productCost":"320","productQty":"2"},{"productId":43,"productCost":"480","productQty":"3"},{"productId":44,"productCost":"420","productQty":"3"}]

当我想插入相同的值时，我希望输出为

[{"productId":43,"productCost":"480","productQty":"3"},{"productId":44,"productCost":"420","productQty":"3"}]

Answer 1

为避免再次推送同一个产品，请先过滤掉可能涉及同一个产品的对象：

let productCost = +document.getElementById('projectcost').value;
let productQty = +document.getElementById('productQty'+id).value;
let product_list = JSON.parse(localStorage.getItem('myItems') ?? "[]");
                       .filter(({productId}) => productId != id)
                       .concat({productId: id, productCost, productQty});
localStorage.setItem('myItems', JSON.stringify(product_list));

如何使用 javascript 替换 localstorage 中的值？

How to replace a value in localstorage using javascript?

javascript

laravel

local-storage