React - setState with certain index - reactjs

Question

I've been stuck for whole day and please help me to fix it.
I have a json data which like this :
[
{
"menu": "menu_1",
"icon": "icon_1",
"detail": {
"name": "name_1",
"phone": "phone_1"
}
},
{
"menu": "menu_2",
"icon": "icon_2",
"detail": {
"name": "name_2",
"phone": "phone_2"
}
},
{
"menu": "menu_3",
"icon": "icon_3",
"detail": {
"name": "name_3",
"phone": "phone_3"
}
}
]
I put them into the "data" state and My goal is I wanna change the "detail" state with certain index ( ex: state "data" with index 1 change the "detail" data )
Currently my code is :
this.setState({
data: {
...this.state.data,
detail:{
this.state.data[1].detail:{
"name": "billy",
"phone": "893823839"
}
}
}
})
That setState is clearly wanna change the state with certain index but fail..
How do I supposed to do?

Answer 1

I guess this is what you're looking for, we could replace an element inside an array using splice :
const index = 1;
this.setState({
data: [...this.state.data].splice(index, 1, {
...this.state.data[index],
details: { name: "billy", phone: "893823839" },
}),
});
Update: we could use slice also to make an immutable update with index :
this.setState({
data: [
...this.state.data.slice(0, index),
{
...this.state.data[index],
details: { name: "billy", phone: "893823839" },
},
...this.state.data.slice(index + 1, this.state.data.length),
],
});
could you try it ?
this is an example that i tested using splice:
const items = [{ id: 1 }, { id: 2 }, { id: 3 }];
const indexToBeModified = 1; // { id: 2 } ==> { foo: "foo", id: 2 }
items.splice(indexToBeModified, 1, { ...items[indexToBeModified], foo: "foo" });
console.log("items", items);

Answer 2

Here is a little modified example. It uses prevState to prevent any unwanted changes that may happen when directly interacting with this.state.
import React, { Component } from "react";
export default class App extends Component {
constructor() {
super();
this.state = {
data: [
{
menu: "menu_1",
icon: "icon_1",
detail: {
name: "name_1",
phone: "phone_1"
}
},
{
menu: "menu_2",
icon: "icon_2",
detail: {
name: "name_2",
phone: "phone_2"
}
},
{
menu: "menu_3",
icon: "icon_3",
detail: {
name: "name_3",
phone: "phone_3"
}
}
]
};
this.modifyData = this.modifyData.bind(this);
}
modifyData(index) {
this.setState((prevState) => {
prevState.data[index].detail={
name: "billy",
phone: "893823839"
};
return {
data: [prevState.data]
};
},()=>{console.log(this.state.data)});
}
render() {
return (
<button onClick={() => this.modifyData(0)}>Click to modify data</button>
);
}
}
Here is a code sandbox reference.