做的一部分，而陳述不增加我的計數正確嗎？

Question

我正在嘗試使用do while語句（在此需要）陳述某人獲得的分數，但是在我的do語句中嵌套的if語句似乎沒有遞增正確（即無論如何它都會給出0％ ）？我錯誤地寫了什麼是不增加我的正確變量？

這裏是我的代碼如下

Scanner input = new Scanner(System.in); 
int q1 = 2, //answer 1 correct answer 
q2 = 1, //answer 2 correct answer 
q3 = 3, //answer 3 correct answer 
correct = 0, //amount correct 
answer1, //store answer1 
answer2, //store answer2 
answer3; //store answer 3 

System.out.printf("%n Question #1.) What is the capital of Iowa?"); //display question 
System.out.printf("%n 1.) Iowa City \t 2.) Des Moines \t 3.) Dubuque"); //display answer 
System.out.printf("%n Your answer: "); 
answer1 = input.nextInt(); //input becomes initial value 

while (answer1 < 1 || answer1 > 3) //while loop to check if answer is valid 
{ 
System.out.printf("%n Invalid Answer please enter a valid answer: "); //ask for input if not valid 
answer1 = input.nextInt(); 
} 

switch (answer1) //switch statement for input types of answer1 
{ 
case 1: 
    System.out.printf("%n Incorrect"); //if input 1 it is incorrect 
    break; //go to next part of code 

case 2: 
    System.out.printf("%n Correct"); //if input 2 it is correct 
    break; 

case 3: 
    System.out.printf("%n Incorrect"); //if input 3 it is incorrect 
    break; 
} 


System.out.printf("%n Question #2.) Where is Iowa?"); //display question 
System.out.printf("%n 1.) Midwest \t 2.) South \t 3.) Northeast"); //display answer 
System.out.printf("%n Your answer: "); 
answer2 = input.nextInt(); //input becomes initial value 

while (answer2 < 1 || answer2 > 3) //make sure answer is valid 
{ 
System.out.printf("%n Invalid Answer please enter a valid answer: "); //ask for valid input 
answer2 = input.nextInt(); 
} 

switch (answer2) //switch statement for chosen answers 
{ 
case 1: 
    System.out.printf("%n Correct"); //correct if input is 1 
    break; 

case 2: 
    System.out.printf("%n Incorrect"); //incorrect for answer 2 
    break; 

case 3: 
    System.out.printf("%n Incorrect"); //incorrect for answer 3 
    break; 
} 

System.out.printf("%n Question #3.) Who is the new president of UIowa?"); //display question 
System.out.printf("%n 1.) Sally Mason \t 2.) Barack Obama \t 3.) Bruce Harreld"); //display answer 
System.out.printf("%n Your answer: "); 
answer3 = input.nextInt(); //input becomes initial value 

while (answer3 < 1 || answer3 > 3) //make sure valid answer 
{ 
System.out.printf("%n Invalid Answer please enter a valid answer: "); //ask for valid answer 
answer3 = input.nextInt(); 
} 

switch (answer3) //switch to give output depending on answer 
{ 
case 1: 
    System.out.printf("%n Incorrect"); //if input is 1 
    break; 

case 2: 
    System.out.printf("%n Incorrect"); //if input is 2 this statement 
    break; 

case 3: 
    System.out.printf("%n Correct"); //if input is 3 this statement 
    break; 
} 

do { 
if (answer1 == q1) { 
    correct++; 
} 
if (answer2 == q2) { 
    correct++; 
} 
if (answer3 == q3) { 
    correct++; 
} 
} while (correct <= 3); 
if (correct == 3) { 
System.out.printf("%n 100%%"); 
} else if (correct == 2) { 
System.out.printf("%n 66.67%%"); 
} else if (correct == 1) { 
System.out.printf("%n 33.33%%"); 
} else { 
System.out.printf("%n 0%%"); 
} 
} //end method 
} //end class 

Answer 1

的主要問題是，你實際上並不需要的do-while循環 - 刪除它，正確的結果會顯示出來。

發生了什麼事情，而你繼續循環，直到正確的變量值爲4或更多。 （也就是說，如果沒有問題被正確回答，你會有一個無限循環。）當你的邏輯去打印結果時，糾正值爲4或更大意味着沒有觸發if條件，導致最終的其他執行並顯示0％。

還有很多其他方法可以簡化和改進你的代碼 - 我假設你只是在學習語言。