如何正确保存您的 println 调试？

Question

I normally spend a lot of time println debugging my programs to make sure they do what I believe. However, when I am done with the debugging there are a lot of unnecessary println's everywhere. Is there some way of not throwing this work away and still have it for later? I know that you could write unit test for this and stick the "println's" there, but I would rather not set up a framework for every little program I write.

My suggestion would be to have a debug file and a clean file and just save both. Does anyone else have a nice idea for this? As an example, here is my almost finished scala program for solving the "Sherlock and the Valid String" on Hackerrank see here .

import java.io.PrintWriter
import scala.collection.mutable.ListBuffer
import scala.collection.mutable.{Set => MutSet}
import scala.collection.mutable.{Map => MutableMap}
import scala.collection.mutable.{ListBuffer}


object Solution {

    /**
        @TODO  "Sherlock and the Valid String", Strings
    */


    // Complete the isValid function below.
    def isValid(s: String): String = {
        // Count frequencies
        var freqmap = Map[Char, Int]()
        var old = 0
        for (c <- s) {
            old = freqmap.getOrElse(c, 0) + 1
            freqmap = freqmap + (c -> old)
        }
        println(s"Counts of characters in string:\n" + freqmap.mkString(", \n"))

        // Check if problems or okay
        var oneDeviation = false
        var initFreq = freqmap(s(0))
        val allowedFreqs = ListBuffer(initFreq)
        val counter = MutableMap[Int, Int](initFreq -> 1)
        var isFreqOne = false
        var freqThatIsOne: FreqIsOne = None

        println(s"Init freq: $initFreq")
        println(s"counter: " + counter.mkString(", \n"))
        println()
        for (freq <- freqmap.values) {
            println("------------------")
            println(s"Freq: $freq")

            if (!oneDeviation) {
                if (freq != initFreq) {
                    oneDeviation = true
                    // greater than 1 diff and no freq is 1 , eg 2 and 4
                    // if pass this we know diff is 1
                    if (isBiggerThanOneDiffAndNoOneFreq(initFreq, freq)) {
                        return "NO"
                    }
                    // check if we have a freq that is one
                    if (initFreq == 1 || freq == 1) {
                        // one freq which is 1
                        if (initFreq == 1) {
                            isFreqOne = true
                            freqThatIsOne = Init
                            // only freq allowed
                            allowedFreqs.remove(0)
                            allowedFreqs += freq
                        } else if (freq == 1) {
                            isFreqOne = true
                            freqThatIsOne = Freq
                            // only allowed is initFreq
                        }
                    // one diff but larger than 1 freqs, only allowed
                    // is the lower frequency
                    } else {
                        if (freq > initFreq) {
                            allowedFreqs.remove(0)
                            allowedFreqs += freq
                        }
                    }

                // no new freq
                } else {

                }
            } else {
                if (!allowedFreqs.contains(freq)) return "NO"
            }
            old = counter(initFreq)
            counter(initFreq) = old + 1
            println(s"counter: " + counter.mkString(", "))
        }
        "YES"
    }

    def isBiggerThanOneDiffAndNoOneFreq(initFreq: Int, freq: Int): Boolean = {
        math.abs(freq - initFreq) > 1 && (initFreq != 1 && freq != 1)
    }

    sealed trait FreqIsOne
    case object Init extends FreqIsOne
    case object Freq extends FreqIsOne
    case object None extends FreqIsOne

    def main(args: Array[String]) {
        val stdin = scala.io.StdIn


        val s = stdin.readLine

        val result = isValid(s)
        println(result)

    }
}

Answer 1

Use a logging framework that allows control over log level for each component (eg scala-logging ) and leave the debugging code there in case you need it again.