完成后输出一次答案，而不是在每一行

Question

我运行以下脚本并打印文件中每一行的输出，但我需要在完成后输出一次答案，而不是在每一行上。有人请帮帮我

const fs = require("fs");
const readline = require("readline");
const stream = require("stream");

const filename = process.argv[2];
const instream = fs.createReadStream(filename);
const outstream = new stream();
outstream.readable = true;
outstream.writable = true;

const rl = readline.createInterface({
  input: instream,
  output: outstream,
  terminal: false,
});
const obj = {};
rl.on("line", function (line) {
  const [country] = line.split(",", 1);
  {
    for (let i = 0; i < [country].length; i++)
      if (obj[country] != null) {
        obj[country] += 1;
      } else {
        obj[country] = 1;
      }
  }
  console.log(obj);
});

Answer 1

可以使用close事件，该事件在读流关闭并处理完毕后调用。

rl.on("close", function (line) {
  console.log(obj);
});