在 Node.js 中使用 readline

Question

我试图readline在 else if 语句中使用：

var rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout
});

rl.question("Would you like to see which cars are available? Please type yes/no: ", function(answer) {

    if (answer === 'yes') {
    // if yes do something
    } else if(answer === 'no') {
        rl.question("Would you like to search by latitude or longitude instead? If yes, please type latitude and longitude: ");
    } else {
        console.log("No worries, have a nice day");
    }

    rl.close();
});

如果用户键入“否”，向用户提出不同问题的正确方法是什么？

目前，如果用户键入否，则不会询问第二个问题。

Answer 1

如果我要这样做，我将首先制作 readLine 问题函数的基于承诺的版本：

const question = (str) => new Promise(resolve => rl.question(str, resolve));

我会将它构建为一组步骤：

const steps = {
  start: async () => {
    return steps.seeCars();
  },
  seeCars: async () => {
    const seeCars = await question("Would you like to see which cars are available? Please type yes/no: ");
    if (seeCars === 'yes') { return steps.showCars(); }
    if (seeCars === 'no') { return steps.locationSearch(); }
    console.log('No worries, have a nice day');
    return steps.end();
  },
  showCars: async () => {
    console.log('showing cars');
    return steps.end();
  },
  locationSearch: async () => {
    const longlat = await question("Would you like to search by latitude or longitude instead? If yes, please type latitude and longitude: ");
    return steps.end();
  },
  end: async () => {
    rl.close();
  },
};

如果您不熟悉异步函数，请注意您必须await在问题之前键入以指示节点在问题得到答案解决之前不要继续。

另请注意，每当我们更改步骤时，您都需要进行更改，return以免步骤的其余部分运行。

这是供您复制和使用的完整程序：

const readline = require('readline');

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout,
});

// Create a promise based version of rl.question so we can use it in async functions
const question = (str) => new Promise(resolve => rl.question(str, resolve));

// A list of all the steps involved in our program
const steps = {
  start: async () => {
    return steps.seeCars();
  },
  seeCars: async () => {
    const seeCars = await question("Would you like to see which cars are available? Please type yes/no: ");
    if (seeCars === 'yes') { return steps.showCars(); }
    if (seeCars === 'no') { return steps.locationSearch(); }
    console.log('No worries, have a nice day');
    return steps.end();
  },
  showCars: async () => {
    console.log('showing cars');
    return steps.end();
  },
  locationSearch: async () => {
    const longlat = await question("Would you like to search by latitude or longitude instead? If yes, please type latitude and longitude: ");
    return steps.end();
  },
  end: async () => {
    rl.close();
  },
};

// Start the program by running the first step.
steps.start();