我的功能总是告诉我，我的问题出错了。 为什么？

Question

I made a function that will quizzes you on Pi. For every digit you write correctly, you get half of a point. However, even if I just type '3', it'll say that I did it incorrectly. Please help.

 function pi() { var piWithoutDecimals = 31415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679; var yourAnswer = prompt("Pi Bonus! Half of a point for every digit of pi that you can write from memory!"); var yourAnswerNum = parseInt(yourAnswer); var yourAnswerMultiplier = yourAnswerNum.toString().split("."); var yourAdjustedAnswer = yourAnswerNum*(10**parseInt(yourAnswerMultiplier)); var yourAdjustedAnswerCount = yourAdjustedAnswer.toString().length; var yourSectionOfpiWithoutDecimals = piWithoutDecimals.toString().substring(0,parseInt(yourAdjustedAnswer-1)); if(yourSectionOfpiWithoutDecimals==yourAnswerNum) { alert("Nice!! You listed "+yourAdjustedAnswerCount+" digits of Pi, and so you get "+Math.floor((yourAdjustedAnswerCount)/2)+" points!") points+=Math.floor((yourAdjustedAnswerCount)/2); } else { alert("Good try, but you got one or more digits incorrect.") } } pi() 

Answer 1

You might have a simple approach.

1. Define your pi in a string
2. Take user input
3. Check if your pi string starts with what user have input
4. Remove decimal point . , and count length to get number of correctly entered digits.
5. Display output of your quiz

 function pi() { const pi = "3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679"; const yourAnswer = prompt("Pi Bonus! Half of a point for every digit of pi that you can write from memory!"); if(pi.startsWith(yourAnswer)) { const yourAdjustedAnswerCount = yourAnswer.replace('.', '').length; alert(`Nice!! You listed ${yourAdjustedAnswerCount} digits of Pi, and so you get ${Math.floor(yourAdjustedAnswerCount / 2)} points!`) } else { alert("Good try, but you got one or more digits incorrect.") } } pi() 

Answer 2

You first go wrong at this line:

var yourAnswerMultiplier = yourAnswerNum.toString().split(".");

If you log this value for eg the input "314" , you'll get the array ["314"] (your probably wanted .split("") ). Going from there, yourAdjustedAnswer will be Infinity (since 10 ** 314 is too large and simply overflows). This fails which is obviously not what you wanted.

As a suggestion, try to step through the execution for a simple example using the developer tools of your browser/IDE and watch closely if each step is according to your expectation.

@Orkhan Alikhanov's answer might also provide some hints.

  function pi() { var piWithoutDecimals = 31415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679; var yourAnswer = prompt("Pi Bonus! Half of a point for every digit of pi that you can write from memory!"); var yourAnswerNum = parseInt(yourAnswer); var yourAnswerMultiplier = yourAnswerNum.toString().split("."); var yourAdjustedAnswer = yourAnswerNum*(10**parseInt(yourAnswerMultiplier)); console.log(yourAdjustedAnswer) var yourAdjustedAnswerCount = yourAdjustedAnswer.toString().length; var yourSectionOfpiWithoutDecimals = piWithoutDecimals.toString().substring(0,parseInt(yourAdjustedAnswer-1)); if(yourSectionOfpiWithoutDecimals==yourAnswerNum) { alert("Nice!! You listed "+yourAdjustedAnswerCount+" digits of Pi, and so you get "+Math.floor((yourAdjustedAnswerCount)/2)+" points!") points+=Math.floor((yourAdjustedAnswerCount)/2); } else { alert("Good try, but you got one or more digits incorrect.") } } pi()