dnsPromises.resolve4(hostname[, options])

• hostname <string> 要解析的主机名。
• options <Object>
  • ttl <boolean> 检索每条记录的生存时间值 (TTL)。 当为 true 时，Promise 使用 { address: '1.2.3.4', ttl: 60 } 对象数组而不是字符串数组进行解决，TTL 以秒表示。

使用域名系统协议为 hostname 解析 IPv4 地址（A 记录）。 当成功时，Promise 使用 IPv4 地址数值（例如 ['74.125.79.104', '74.125.79.105', '74.125.79.106']）解决。

• hostname <string> Host name to resolve.
• options <Object>
  • ttl <boolean> Retrieve the Time-To-Live value (TTL) of each record. When true, the Promise is resolved with an array of { address: '1.2.3.4', ttl: 60 } objects rather than an array of strings, with the TTL expressed in seconds.

Uses the DNS protocol to resolve IPv4 addresses (A records) for the hostname. On success, the Promise is resolved with an array of IPv4 addresses (e.g. ['74.125.79.104', '74.125.79.105', '74.125.79.106']).