Golang小项目-算数测验

问题描述

在命令行界面，给出12道数学加法算数题（这12道数学题目来自于problems.csv这个文件），最后12道题目做完，能够给出最后最终的得分，实验最终实现的效果如下图。

关键技能点

csv文件读取，命令行参数解析，字典

该项目下有两个文件

在main.go文件中，全部的实现代码如下

package main

import (
    "bufio"
    "encoding/csv"
    "flag"
    "fmt"
    "log"
    "os"
    "strings"
    "time"
)

var (
    //加一个定时，如果30秒内没有答题，就报告超时
    //关于flag的用法详见  http://www.cppblog.com/kenkao/archive/2017/06/21/215013.html
    // set flags
    csvPath = flag.String("csv", "problems.csv", "a csv file in the format of 'question,answer'")
    limit   = flag.Int("limit", 30, "the time limit for the quiz in seconds'")
)

func main() {
    //通过调用flag.Parse()来进行对命令行参数的解析
    // parse the flags
    flag.Parse()

    // open the csv file
    file, err := os.Open(*csvPath)
    if err != nil {
        log.Println(err)
        return
    }
    defer file.Close()

    // open the csv file
    csvReader := csv.NewReader(file)
    // parse the csv file
    csvData, err := csvReader.ReadAll()
    if err != nil {
        log.Println(err)
        return
    }

    // put question/answer pairs into a map where questions are keys and answers are values
    //map这里会把读取的东西转换为字典，for循环中_这里替换的是key，也就是序号1234
    qaPair := make(map[string]string, len(csvData))
    for _, data := range csvData {
        qaPair[data[0]] = data[1]
    }

    // create a ticker for the time limit and a channel to signal the user finished the quiz
    ticker := time.NewTicker(time.Second * time.Duration(*limit))
    done := make(chan bool)

    // create a scanner for user input
    scanner := bufio.NewScanner(os.Stdin)

    var userAnswer string
    qNum, numCorrect := 0, 0
    go func() {
        // iteration order for maps in go is randomized so the questions won't be in the same order every time
        for question, answer := range qaPair {
            qNum++
            // ask a question
            fmt.Printf("Problem #%d: %s = ", qNum, question)
            // get an answer
            scanner.Scan()
            userAnswer = scanner.Text()
            // trim leading and trailing whitespace
            //TrimSpace的作用就是去除空格等符号
            userAnswer = strings.TrimSpace(userAnswer)
            userAnswer = strings.ToLower(userAnswer)
            answer = strings.ToLower(answer)
            // check the answer
            if answer == userAnswer {
                numCorrect++
            }
        }
        done <- true
    }()

    // select chooses the first channel with an available value
    // if done is available first, the user finished
    // if ticker is available first, the time limit has been reached
    select {
    case <-done:
    case <-ticker.C:
        fmt.Println("time's up!")
    }

    // print the results
    fmt.Printf("You scored %d out of %d.\n", numCorrect, len(qaPair))
}

参考链接：
Quiz Game