Change a value from a nested object using localstorage

Question

I have this code that set the obj value in localstorage.

 const obj = { name: "Bill", meta: { age: 18 } }; const data = localStorage.setItem('user', JSON.stringify(obj));

Now i want to change the age key in the localstorage: localStorage.setItem('user', JSON.stringify({...data, ...data.meta.age= 15 } })); , but it does not work.
How to change the value above and to see the changes in localstorage?

Answer 1

Assuming you have data , the problem is that ...data.meta.age = 15 is a syntax error. You don't use = in object literals, and it does't make sense to try to spread the age property (which is a number). Instead:

const newData = {
    ...data,
    meta: {
        ...data.meta,
        age: 15,
    },
};
localStorage.setItem("user", JSON.stringify(newData));

Notice how we have to create a new outermost object and also a new object for meta .

Live Example:

 const data = { name: "Bill", meta: { occupation: "Programmer", // Added so we see it get copied age: 18, }, }; const newData = {...data, meta: {...data.meta, age: 15, }, }; console.log(newData);