Question

document.body.innerHTML = "An error occurred. Please try to login again.<br>"; 

document.body.innerHTML += 'Username: <input type="text" name="username"><br>'; 
document.body.innerHTML += 'Password: <input type="password" name="password"><br>'; 
document.body.innerHTML += "<input type='submit' value='Login' onclick='alert(document.getElementById('password').value)'>" 

運行該代碼，然後點擊登錄按鈕後，Chrome的JavaScript控制檯還給：

SyntaxError: expected expression, got '}'

我怎樣才能解決呢？

Answer 1

您需要更改報價，並逃離他們的JavaScript代碼中：

document.body.innerHTML = "An error occurred. Please try to login again.<br>"; 
 

 
document.body.innerHTML += 'Username: <input type="text" name="username"><br>'; 
 
document.body.innerHTML += 'Password: <input type="password" name="password" id="password"><br>'; 
 
document.body.innerHTML += "<input type='submit' value='Login' onclick='alert(document.getElementById(\"password\").value)'>";

As for the reason "why the browser throws this specific error?", here is the question:

因爲代碼是錯誤的，瀏覽器實際看到下面的代碼：

(function(event){alert(document.getElementById(
}) 

正如你所看到的 - 在document.getElementById(有一個關閉{，這是您的瀏覽器正在向您大喊大叫。

Answer 2

只是逃避報價

document.body.innerHTML = "An error occurred. Please try to login again.<br>"; 
 

 
document.body.innerHTML += 'Username: <input type="text" name="username"><br>'; 
 
document.body.innerHTML += 'Password: <input type="password" name="password" id="password"><br>'; 
 
document.body.innerHTML += "<input type='submit' value='Login' onclick='alert(document.getElementById(\"password\").value);return false;' />"