如何在JavaScript中同时和for循环嵌套

Question

Just learning javascript and having a hard time with this code would like to make it repeat 5 times different random math questions but only continue to the next question if answered correctly. can somebody help point me in the right direction?

// var initialization
var num1 = Math.floor(Math.random()*100)+1;
var num2 = Math.floor(Math.random()*100)+1;
var correct = num1 + num2;
var guess = 0;
var count = 1;
var msg = " ";
//var debug = 5;

// loop basic math process

while(count <= 1){

guess = eval(prompt("What is "+num1+" + "+num2+" = __ ?"));

    if(guess != correct){
        msg = alert("Sorry please try again");

    }else{
        msg = alert("By George I think you got it!");

        for(i=0;i<=5;i+=1){
            alert(debug);
            var num1 = Math.floor(Math.random()*100)+1;
            var num2 = Math.floor(Math.random()*100)+1;
            var correct = num1 + num2;

            guess = eval(prompt("What is "+num1+" + "+num2+" = __ ?"));

        if(guess != correct){
            alert("Sorry please try again");

        }else{
            alert("Great your on a roll!");

        }}} count++;
}

Answer 1

From your coding, I suppose you don't need the outer while loop. And if you do need while loop to control the total rounds of for loop, you should better wrap the whole for loop code in an individual function.

Answer 2

If you want to keep asking until they get the question right, then you are going to need two loops. One to count the 5 questions. And one inside of the that to keep asking the question until it is correct I think you have your loops kind of inverted. I would instead do something like the following:

for(i=0;i<=5;i+=1){
    alert(debug);
    var num1 = Math.floor(Math.random()*100)+1;
    var num2 = Math.floor(Math.random()*100)+1;
    var correct = num1 + num2;
    var guess = -1;

    while (guess != correct) {    
        guess = eval(prompt("What is "+num1+" + "+num2+" = __ ?"));
        if(guess != correct){
            msg = alert("Sorry please try again");
        }else{
            msg = alert("By George I think you got it!");
        }
    }
}

If you wanted to know if they got several right in a row to change the message you would have to detect if they were on a streak:

var streak = 0;


    while (guess != correct) {    
        guess = eval(prompt("What is "+num1+" + "+num2+" = __ ?"));
        if(guess != correct){
            msg = alert("Sorry please try again");
            streak = 0;
        }else{
            streak++;
            if (streak < 2) {
                msg = alert("By George I think you got it!");
            } else {
                msg = alert("Keep up the good work!");
            }
        }
    }

Answer 3

Just as a hint -- if your editor doesn't have the ability to reformat/re-indent source code, jsbeautifer.org does a wonderful job.

var num1;
var num2;
var guess;
var correct;
var msg;

// Bonus
// It looked like you were trying to give different responses so it wasn't 
// quite as boring

var successMessages = [
  "Way to go!",
  "Alright!",
  "Cheers!",
  "Tally ho!"
  "Well done, old boy"
];

var questionsLeft = 5;

// loop basic math process
while (questionsLeft !== 0) {

  num1 = Math.floor(Math.random() * 100) + 1;
  num2 = Math.floor(Math.random() * 100) + 1;
  correct = num1 + num2;

  guess = prompt("What is " + num1 + " + " + num2 + " = __ ? ");
  guess = parseInt(guess, 10); // Convert to a number

  if (guess !== correct) {
    msg = alert("Sorry please try again ");
  } else {
    msg = successMessages[questionsLeft];
    questionsLeft--;
  }
}

Or, if you want to make them repeat the question:

var num1;
var num2;
var guess;
var correct;
var msg;
var isRight;

// Bonus
// It looked like you were trying to give different responses so it wasn't 
// quite as boring

var successMessages = [
  "Way to go!",
  "Alright!",
  "Cheers!",
  "Tally ho!"
  "Well done, old boy"
];

var questionsLeft = 5;

// loop basic math process
while (questionsLeft !== 0) {

  num1 = Math.floor(Math.random() * 100) + 1;
  num2 = Math.floor(Math.random() * 100) + 1;
  correct = num1 + num2;

  // They haven't answered yet, so they can't be right.
  isRight = false;

  while (!isRight) {
    guess = prompt("What is " + num1 + " + " + num2 + " = __ ? ");
    guess = parseInt(guess, 10); // Convert to a number

    isRight = guess !== correct

    if (isRight) {
      msg = alert("Sorry please try again ");
    } else {
      msg = successMessages[questionsLeft];
      questionsLeft--;
    }
  }
}

Answer 4

Try this:

var num1 = [], num2 = [], correct = [], count = 0, guess;
for(var i=0; i<5; i++){
  num1[i] = Math.floor(Math.random()*101);
  num2[i] = Math.floor(Math.random()*101);
  correct[i] = num1[i]+num2[i];
}
while(count < 5){
  quess = prompt('What is '+num1[count]+'+'+num2[count]+' ?');
  if(+quess === correct[count]){
    alert('You are Correct!');
    if(++count === 5)alert('You Have Completed All of the Answers Correctly!!!');
  }
  else{
    alert('Please Try Again.')
  }
}