Using functional setState in forms - reactjs

Question

I have been learning react and on setState i get about functional setState, i wanted to implement this on the forms to see how it works ( please don't give me counter example,i am seeing if it can be implemented in forms for usage only ).
I am trying to do this because i saw similar approach in a github but he had included all the things inside the single object, so he is doing it easily. But my question is can i do the same but without including my form properties like username and password inside object. I am talking about this repo => Form Container. What do you people recommend? How may i can do ? Thanks !
My form code is like this:
index.js
import React,{ Component } from 'react';
import ReactDOM from 'react-dom';
class Form extends Component{
constructor(props){
super(props);
this.state = {
name: "",
age: "",
};
}
handleInput = (e) => {
let name = e.target.name;
let value = e.target.value;
this.setState({ [name]: value });
}
//The block where i am trying to implement the function setState
handleInput = (e) => {
let name = e.target.name;
let value = e.target.value;
this.setState( state => ({
name:{state.name,[name]: value}
}));
}
render(){
return(
<div>
<label> Name:
<input type="text" name="name" value={this.state.name} onChange={this.handleInput} />
</label>
<br />
<label> Age:
<input type="text" name="age" value={this.state.age} onChange={this.handleInput} />
</label>
</div>
);
}
}
ReactDOM.render(<Form />, document.getElementById('root'))

Answer 1

handleInput = ({ target }) => {
const { name, value } = target;
this.setState({ [name]: [value] });
}
//Can even boil down to one line of code
handleInput = ({ target }) => this.setState({ [target.name]: [target.value] })
You may try the code above. It's pretty concise and not sure how to elaborate on it. We can discuss about my approach in comment
UPDATES:
let value = e.target.value;
this.setState( prevState => ({
newUser : { ...prevState.newUser, name: value }
}), () => console.log(this.state.newUser))
The above code was copied from the link you commented which in our case, should be implemented as below:
handleInput = ({ target }) => {
const { name, value } = target;
this.setState(prevState => ({ ...prevState, [name]: value }));
}