Exemple d'utilisation de l'opérateur de chaînage optionnel

null_safety_chaining_operator.js

let pokemon = {
    name: "Bulbasaur",
    type: [
      "Grass",
      "Poison"
    ],
    base: {
      hp: 45,
      attack: 49,
      defense: 49,
      specialAttack: 65,
      specialDefense: 65,
      speed: 45
    }
  };
  
  
//Plutôt que d'écrire ...
if (pokemon && pokemon.name && pokemon.base && pokemon.base.specialDefense) {
    console.log(`The pokemon name is ${pokemon.name} and its special defense amount to ${pokemon.base.specialDefense}`);
}
  
//... on peut écrire
if (pokemon?.name && pokemon?.base?.specialDefense) {
    console.log(`The pokemon name is ${pokemon.name} and its special defense amount to ${pokemon.base.specialDefense}`);
}
  
pokemon.base = null;

if (pokemon?.name && pokemon?.base?.specialDefense) {
    console.log(`The pokemon name is ${pokemon.name} and its special defense amount to ${pokemon.base.specialDefense}`);
} else {
    console.log("Cannot display anything, something is null or undefined");
}