js判断网络超时

var xhr = new XMLHttpRequest();
xhr.open('GET', 'your_url', true);
xhr.timeout = 5000; // 设置超时时间为5秒

xhr.onreadystatechange = function() {
    if (xhr.readyState === 4) {
        if (xhr.status === 200) {
            console.log('请求成功');
        } else {
            console.log('请求失败');
        }
    }
};

xhr.ontimeout = function() {
    console.log('请求超时');
};

xhr.send();

function fetchWithTimeout(url, options, timeout = 5000) {
    return Promise.race([
        fetch(url, options),
        new Promise((_, reject) =>
            setTimeout(() => reject(new Error('请求超时')), timeout)
        )
    ]);
}

fetchWithTimeout('your_url', {}, 5000)
    .then(response => response.json())
    .then(data => console.log(data))
    .catch(error => console.log(error.message));