无法在数组中添加元素

Question

我正在尝试在我的电脑上添加可用端口，用于 Arduino 和电脑之间的串行通信。 我已将 portsList 创建为数组变量，并将这些端口推送到该变量中。 但最后，我得到的数组长度为 0。我使用的是串口节点模块。

const SerialPort = require("serialport");

var portsList = [];
SerialPort.list().then((ports) => {
  ports.forEach((port) => {

    var portInfo = {
      portPath: port.path,
      portManufacturer: port.manufacturer,
    };

    portsList.push(portInfo);
    console.log("Port: ", portInfo);
  });
});

console.log(portsList.length);

代码的output为：

Answer 1

尝试这个：

    portsList.push({
      portPath: port.path,
      portManufacturer: port.manufacturer,
    });
    console.log("Port: ", portInfo);

Answer 2

SerialPort.list() 似乎是异步的。 将控制台放在“forEach”之后

const SerialPort = require("serialport");

var portsList = [];
SerialPort.list().then((ports) => {
  ports.forEach((port) => {

    var portInfo = {
      portPath: port.path,
      portManufacturer: port.manufacturer,
    };

    portsList.push(portInfo);
    console.log("Port: ", portInfo);
  });
  console.log(portsList.length);
});

或等待列表，

const SerialPort = require("serialport");
     
const getPortsList = async () => {
  var portsList = [];
  const ports = await SerialPort.list();

  ports.forEach((port) => {

    var portInfo = {
      portPath: port.path,
      portManufacturer: port.manufacturer,
    };

    portsList.push(portInfo);
    console.log("Port: ", portInfo);
  });

  console.log(portsList.length);
}

getPortsList();