node.js "delete"的奇怪语法

Question

删除有什么用？我以前没有见过这样的语法，有人可以帮助我吗？代码片段非常简单，使用了node.js、mongoose、mongodb

function _update(game, callback) {
    if (!game) {
        callback(new Error("Game must be provided."));
        return;
    }
    if (!game.gameId) {
        callback(new Error("Game id should be provided"));
        return;
    }

    var updates = (game instanceof Game) ? game.toObject() : game;
    delete updates._id;
    updates.modifiedDate = new Date();

    Game.findOneAndUpdate({"_id": game.id, "deleted" : {"$ne": true}}, updates, callback);
}

Answer 1

JavaScript 中的

删除 removes the property from the object .

var game = {
    id: 1
}

console.log(game);  // Object {id: 1}

delete game.id

console.log(game);  // undefined