Correct Way of Updating States(Using spread Operator)

[chaesthetics]

import { useState } from "react"; 

export default function App() { 
  const [greeting, setGreeting] = useState({ greet: "Hello, World" }); 
  console.log(greeting, setGreeting); 

  function updateGreeting() { 
    const newGreeting = {...greeting}; 
    newGreeting.greet = "Hello, World-Wide Web"; 
    setGreeting(newGreeting); 
  } 

  return ( 
    <div> 
      <h1>{greeting.greet}</h1> 
      <button onClick={updateGreeting}>Update greeting</button> 
    </div> 
  ); 
} 

[chaesthetics]

import { useState } from "react"; 

export default function App() { 
  const [greeting, setGreeting] = useState( 
    { 
        greet: "Hello", 
        place: "World" 
    } 
  ); 
  console.log(greeting, setGreeting); 

  function updateGreeting() { 
    setGreeting(prevState => { 
        return {...prevState, place: "World-Wide Web"} 
    }); 
  } 

  return ( 
    <div> 
      <h1>{greeting.greet}, {greeting.place}</h1> 
      <button onClick={updateGreeting}>Update greeting</button> 
    </div> 
  ); 
} 

[chaesthetics]

import { useState } from "react";

export default function App() {
  const [giftCard, setGiftCard] = useState(
    {
        firstName: "Jennifer",
        lastName: "Smith",
        text: "Free dinner for 4 guests",
        valid: true,
        instructions: "To use your coupon, click the button below.",
    }
  );

  function spendGiftCard() {
    setGiftCard(
      prevState => {
        return {...prevState, instructions: "Your coupon has been used.", valid: false};
     }
    )
  }

  return (
    <div style={{padding: '40px'}}>
      <h1>
        Gift Card Page
      </h1>
      <h2>
        Customer: {giftCard.firstName} {giftCard.lastName}
      </h2>
      <h3>
        {giftCard.text}
      </h3>
      <p>
        {giftCard.instructions}
      </p>
      {
        giftCard.valid && (
          <button onClick={spendGiftCard}>
            Spend Gift Card
          </button>
        )
      }
    </div>
  );
}

[chaesthetics]