未捕获的TypeError:无法设置未定义的属性(设置“”_DT_CellIndex“”)

if (myObject !== undefined) {
    myObject._DT_CellIndex = someValue;
} else {
    console.error("myObject is undefined");
}

myObject?._DT_CellIndex = someValue;

async function initializeAndSetProperty() {
    const myObject = await initializeObject();
    if (myObject !== undefined) {
        myObject._DT_CellIndex = someValue;
    } else {
        console.error("myObject is undefined");
    }
}

console.log("Before setting property:", myObject);
if (myObject !== undefined) {
    myObject._DT_CellIndex = someValue;
} else {
    console.error("myObject is undefined");
}

async function initializeObject() {
    // 模拟异步操作
    return new Promise((resolve) => {
        setTimeout(() => {
            resolve({ name: "example" });
        }, 1000);
    });
}

async function main() {
    const myObject = await initializeObject();
    console.log("Initialized object:", myObject);
    if (myObject !== undefined) {
        myObject._DT_CellIndex = 1;
        console.log("Property set:", myObject);
    } else {
        console.error("myObject is undefined");
    }
}

main();