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map function not showing elements on screen

i have this part of code the map function did not show any element of the array, if i console.log the variable it shows me the elements but for some reasons i can't show the elements on the screen.
Code
function Solution({list}){
const data = list
console.log(data);
return(
<div>
{
data?.map((item) => {
return (
<div>
<p> {item.title} </p>
</div>
)
})
}
</div>
)
}
export default Solution;
const list = [
{
title: "Home"
},
{
title: "Service",
subItem: ["Clean", "Cook"]
},
{
title: "Kitchen",
subItem: ["Wash", "Dish"]
},
];
Solution({list})

Please, just pass "list" link this.
<Solution list={list}/>
Hope will help you, Thanks)

Check this out
import React from 'react';
function Solution({list}){
const data = list
console.log(list);
return(
<div>
{
data?.map((item) => {
return (
<div key={item.id}>
<p> {item.title} </p>
</div>
)
})
}
</div>
)
}
export function App(props) {
const list = [
{
id:1,
title: "Home"
},
{
id:2,
title: "Service",
subItem: ["Clean", "Cook"]
},
{
id:3,
title: "Kitchen",
subItem: ["Wash", "Dish"]
},
];
return (
<div className='App'>
<Solution list={list} />
</div>
);
}
// Log to console
console.log('Hello console')
Have a unique key prop for each element when you map an array and send list array as props to your Solution component

Struggling in construction the tree hierarchy in react

I wanted to use tree view but I am struggling in construction the tree (hierarchical view of information) in react.
same as https://www.w3schools.com/howto/howto_js_treeview.asp
What I am trying CodeSandBox - https://codesandbox.io/s/unruffled-babbage-9knrz?file=/index.js
JSON - (this is not fixed can be any format)
const data = [
{
title: "Node 1",
childNodes: [
{ title: "Childnode 1.1" },
{
title: "Childnode 1.2",
childNodes: [
{
title: "Childnode 1.2.1",
childNodes: [{ title: "Childnode 1.2.1.1" }]
},
{ title: "Childnode 1.2.2" }
]
}
]
}
];
I have toggle function which expand and vice versa the tree node.
I am struggling in construction the tree in react.
Please guide me.

The first of all you don't need use <Tree/> as the recursive component, instead of it use <Node/>
The second thing in React you don't need to use the querySelector and classList for changing state of a component.
I've implemented my idea in code here
const Tree = () => {
return (
<ul>
{data.map(({ title, childNodes }) => (
<Node key={title} title={title} childNodes={childNodes} />
))}
</ul>
);
};
class Node extends React.Component {
state = {
isOpen: false
};
toggle = () => {
this.setState({
isOpen: !this.state.isOpen
});
};
render() {
const { title, childNodes } = this.props;
const { isOpen } = this.state;
return (
<li>
<span className="caret" onClick={this.toggle}>
{title}
</span>
{childNodes && isOpen && (
<ul>
{childNodes.map(({ title, childNodes }) => (
<Node key={title} title={title} childNodes={childNodes} />
))}
</ul>
)}
</li>
);
}
}
export default Tree

Creating HTML tag in react component

I'm not extending component class, trying to use usestate to manage state. Now I want to add a person component on certain conditions to personList variable inside the method togglePersonsHanler.
I'm expecting a list of HTML tags to be added like
<person name="person1" age=31>
<person name="person2" age=26>
<person name="person3" age=35>
but on console log, I'm getting personList as below
{$$typeof: Symbol(react.element), type: "div", key: null, ref: null, props: {…}, …}$$typeof: Symbol(react.element)type: "div"key: nullref: nullprops: {children: Array(3)}_owner: null_store: {validated: false}_self: null_source: {fileName: "D:\data\react\my-app\src\App.js", lineNumber: 72, columnNumber: 7}
and person tag is not getting added to DOM, any advice, please
import React, { useState } from 'react';
import './App.css';
import Person from './Person/Person';
const App = props => {
const [personState, setPersonState] = useState({
persons: [
{name: "person1", age:31},
{name: "person2", age:26},
{name: "person3", age:25}
],
other: "some Other Value"
} );
const [otherState,setOtherState]=useState({otherState :'some other value'});
const [showPersonsState,setShowPersonsState]=useState({showPersons :false});
let personList=null;
const togglePersonsHanler =() =>{
personList=null;
setShowPersonsState(
{showPersons : !showPersonsState.showPersons}
)
console.log(showPersonsState.showPersons);
if(showPersonsState.showPersons){
personList=(
<div>{personState.persons.map (person =>{
return <person name={person.name} age={person.age}/>
}
)}</div>
);
}
console.log(personList);
}
return (
<div className="App">
<h1> HI, I'm the react app</h1>
<button
//onClick={switchNameHandler.bind(this,'Gopu Ravi')}
onClick={togglePersonsHanler}
style={style}> Toggle Person </button>
{ personList }
</div>
);
}
export default App;

You're mapping the object literals by using them as an html tag. You likely meant to use the imported Person component.
<div>
{personState.persons.map (person => (
<Person name={person.name} age={person.age}/>
)}
</div>
And to fix a react-key warning since all mapped elements need unique keys, add a key prop with a value that is unique to the data in the array, like name:
<div>
{personState.persons.map (person => (
<Person key={name} name={person.name} age={person.age}/>
)}
</div>
To correctly toggle the display of the "personList":
Conditionally render the mapped persons array if showPersonsState is true
Simplify showPersonsState state to simply be the boolean value
Use functional state update to correctly toggle showPersonsState from previous state
Updated component code
const App = props => {
const [personState, setPersonState] = useState({
persons: [
{ name: "person1", age: 31 },
{ name: "person2", age: 26 },
{ name: "person3", age: 25 }
],
other: "some Other Value"
});
const [otherState, setOtherState] = useState({
otherState: "some other value"
});
const [showPersonsState, setShowPersonsState] = useState(false);
const togglePersonsHandler = () => setShowPersonsState(show => !show);
return (
<div className="App">
<h1> HI, I'm the react app</h1>
<button onClick={togglePersonsHandler}>Toggle Person</button>
{showPersonsState &&
personState.persons.map(({ age, name }) => (
<Person key={`${name}`} name={name} age={age} />
))}
</div>
);
};

Adding an Object to an Object's Array and setting the state in React

I am new at React and I come up with an Idea for learning many things in one shot. I have this component, Its initial state is an array with an object of baseball Players, I need to add new baseball Player's name through an Input field to the state and then, once a baseball Player is added, a second component appears with input fields to add data.
How can I do that?
export default class BaseballPlayerList extends React.Component {
constructor() {
super();
this.state = {
baseBallPlayers: [
{
name: "Barry Bonds",
seasons: [
{
year: 1994,
homeRuns: 37,
hitting: 0.294
},
{
year: 1996,
homeRuns: 40,
hitting: 0.294
}
]
}
]
};
this.addPlayer = this.addPlayer.bind(this);
}
addPlayer(e) {
e.preventDefault();
const newPLayer = {
baseBallPlayers: this.state.baseBallPlayers.name,
seasons: []
};
console.log(newPLayer);
this.setState(prevState => ({
baseBallPlayers: [...prevState.baseBallPlayers, newPlayer]
}));
}
render() {
return (
<div>
<div>
<ul>
{this.state.baseBallPlayers.map((player, idx) => (
<li key={idx}>
<PlayerSeasonInfo player={player} />
</li>
))}
</ul>
</div>
<input value={this.state.baseBallPlayers.name} />
<button onClick={this.addPlayer}>AddPlayer</button>
</div>
);
}
}
export default class PlayerSeasonInfo extends Component {
constructor(props) {
super(props);
this.player = this.props.player;
}
render() {
return (
<div>
{this.player && (
<div>
<span>{this.baseBallPlayers.name}</span>
<span>
<input placeholder="year" />
<input placeholder="homeRuns" />
<input placeholder="hitting" />
<button>AddInfo</button>
</span>
</div>
)}
</div>
);
}
}

here do you have a working example: https://codesandbox.io/s/nervous-yonath-9u2d6
the problem was where you where storing the new name and how you where updating the whole players state.
hope the example helps!

React - iterating over key value pairs in array

I cant get this snippet to output tacos
im not sure what I am doing wrong
let tacos = [{ John: "Guacamole" }, { Sally: "Beef" }, { Greg: "Bean" }];
class Parent extends React.Component {
render() {
return (
<div className="parent-component">
<h3>List of tacos:</h3>
<TacosList tacos={tacos} />
</div>
);
}
}
class TacosList extends React.Component {
render() {
return (
<div className="tacos-list">
{this.props.tacos.map((taco) => {
return
<Parent taco={taco}/>
})}
</div>
);
}
}
render(<Parent />, document.getElementById("root"));

Your problem is that you are breaking into a new line in after return which it's returning undefined while iterating the tacos list.
Furthermore, You will create an infinite loop rendering if you call <Parent /> inside <TacosList />
Either you create a new component to render the items or you do it within the <TacosList /> component
let tacos = [{
person: "John",
ingredient: 'Guacamole'
}, {
person: 'Sally',
ingredient: 'Beef'
}, {
person: 'Greg',
ingredient: 'Bean'
}];
class Parent extends React.Component {
render() {
return (
<div className="parent-component">
<h3>List of tacos:</h3>
<TacosList tacos={tacos} />
</div>
);
}
}
class TacosList extends React.Component {
render() {
return (
<div className="tacos-list">
{this.props.tacos.map((taco, index) => (
<p key={index}>{taco.person}: {taco.ingredient}</p>
))}
</div>
);
}
}
ReactDOM.render(<Parent />, document.getElementById("root"));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="root">
</div>

The problem is
<Parent taco={taco}/>
First parent is not expecting a taco property.
Second I think you intend to actually render the elements to display the taco information there, not a Parent component for each taco.

Start up with creating an atomic component (div, span or IMG) to show the tacos list, in TacosList.
The map in TacosList will work only at the first level, because every item is a JavaScript object, which means you have to know the key, to have the value, or use Object.keys and Object.items to show names.