NodeJs服务器上数组中的数据

let arr1 = [1, 2, 3];
let arr2 = arr1.slice(); // 或 let arr2 = arr1.concat();
arr2[0] = 100;
console.log(arr1); // [1, 2, 3]
console.log(arr2); // [100, 2, 3]

const _ = require('lodash');

let arr1 = [1, 2, [3, 4]];
let arr2 = _.cloneDeep(arr1);
arr2[2][0] = 100;
console.log(arr1); // [1, 2, [3, 4]]
console.log(arr2); // [1, 2, [100, 4]]

const fs = require('fs');

const readStream = fs.createReadStream('large-file.txt');
readStream.on('data', (chunk) => {
  // 处理数据块
});
readStream.on('end', () => {
  console.log('处理完成');
});

const async = require('async');

const tasks = [
  (callback) => {
    // 任务1
    callback(null, 'result1');
  },
  (callback) => {
    // 任务2
    callback(null, 'result2');
  }
];

async.parallel(tasks, (err, results) => {
  if (err) throw err;
  console.log(results); // ['result1', 'result2']
});