store and update associative array in state react js

Question

How to update my associative array while the key already exists else I want to create a new key and store that array in the state. I had tried to store a value in the associative array. When I entering data in the input field it can call handleChange after that I want to do that above I mentioned operations

    import React, { Component } from 'react';

        class App extends Component {
            constructor(props) {
                super(props);
                this.onChangeEvent = this.onChangeEvent.bind(this);
                this.onChangeCount = this.onChangeCount.bind(this);
                this.onSubmit = this.onSubmit.bind(this);
                this.state = {
                    name: [],
                    inputCount:5
                }
            }
// associtive array
        handleChange = (e) => {
// I want to check the key is already exist or not if exist means create update the value else create a new key and also I want to validate all the data.
                    const check = e.target.name
                    const value = e.target.value
                    const name = []
                    name[check] = value
                    console.log(name)
                    this.setState({
                        name,
                    })
            }
        render() {
                let options = []
                for (let i = 0; i < this.state.inputCount; i += 1) { options.push(i); }
            return (
{this.state.inputCount && (
                        options1.map((i) => {
                            return (<div key={i}>
                                <input  onChange={this.handleChange} type="text" className="name" name={`name${i}`} placeholder="Name" /><br />
                            </div>)
                        })
                    )}
        );
            }
        }
        export default App;

Answer 1

First, there are no "associative arrays" in JavaScript, though there are Objects, which is basically the same. So right off the bat, you should change the initialization of name to be {} instead of [] .

To check if a key exists in an Object, simply do check in obj or even name.hasOwnProperty(check) , where check is the key you want to check.

Setting and updating a value is done the same way in JavaScript, regardless if the key exists or not: name[check] = value .