爲什麼這段代碼不會在瀏覽器中提示一次？

Question

我正在爲一個叫做「構建測驗」的樹屋挑戰。我必須提出問題，根據用戶的回答，我應該顯示哪些問題他/她是否對錯。我現在特別苦惱的是理解爲什麼下面的JavaScript代碼不會至少支持我的一個問題。 任何有識之士將不勝感激。

// Questions 
var questions = [ 
      ['Who is the President of the U.S?', 'Donald Trump'], 
      ['Who is the Vice President of the U.S?', 'Mike Pence'], 
      ['Who won the Super Bowl last year?', 'Patriots'] 
]; 

//Variables go here, answer, response, question ect 
var correctAnswers = 0; 
var question; 
var answer; 
var response; 
var html; 

function print(message) { 
    document.write(message); 
} 

    //below is how you loop the questions above 
for (var i = 0; i < questions.length; i += 1); { 
    question = questions[i][0]; 
    answer = questions[i][1]; 
    response = window.prompt(question); 
    if (response === answer) { 
     correctAnswers += 1; 
    } 
} 

html = "you got" + correctAnswers + "question(s) right."; 
print(html); 

Answer 1

循環表達式的右括號與代碼塊的開始大括號之間的「for」循環中有一個分號分號。