'await' expressions are only allowed within async functions and at the top levels of modules.

"await" expressions indeed have a specific context in JavaScript. They can only be used inside an `async` function[^1] because they signify that the code following it should pause execution until the associated Promise completes. Here's an example:

// 示例：异步函数中使用await
async function getDataFromAPI() {
    try {
        const response = await fetch('https://api.example.com/data');
        if (response.ok) {
            const data = await response.json();
            // 这里的代码将在fetch成功并解析JSON后运行
            console.log(data);
        } else {
            throw new Error('Failed to fetch data');
        }
    } catch (error) {
        console.error(error);
    }
}

getDataFromAPI(); // 等待Promise解析后再执行后续代码

In the case of module top-levels[^2], you can use `async` functions there as well, but note that any `export` statements must come after all `await` expressions, since they must be able to evaluate without awaiting promises.