我尝试提交而不选择所有数字的任何单选按钮。它应该提醒我7次。但是，我只有6个！它似乎跳过了第5个警报框。而且我不知道原因。谁能帮我？谢谢！
library(data.table)
setDT(x)[,.SD[1:3] , Gender]
答案 0 :(得分：0)
for(i; i < inputs.length; i++){
删除此处i ++
必须是
function checkAnswers(){
var inputs = document.querySelectorAll('input[type="radio"]');
var check = 0;
var score = 0,i=0;
for(i; i < inputs.length; ){
你只是跳过5除了4 - 而且在4次跳跃之后 - 你有+4输入 - 并且跳跃引发了五个问题
答案 1 :(得分：0)
更改
i += 4;
到
i += 3;
因为for(i;i<inputs.length;i++)你已经在i++。
答案 2 :(得分：0)
尝试使用相同的代码：
<html>
<head>
<style type="text/css">
h1{
width:100%;
background-color:maroon;
color:white;
}
fieldset{
width:500px;
margin:auto;
}
</style>
<script>
function checkAnswers(){
var inputs = document.querySelectorAll('input[type="radio"]');
var check = 0;
var score = 0,i=0;
for(i;i<inputs.length;i++){
var inputName = inputs[i].getAttribute("name");
var checker = document.getElementsByName(inputName);
var counter = false;
for(j=0;j<checker.length;j++){
if(checker[j].checked == true){
counter = true;
i += 3;
break;
}
}
if(counter == false){
alert("Must answer question number" + " " + inputName +"!");
document.getElementById('HG-' + inputName).style.backgroundColor = "red";
i += 3;
check++;
}
else{
document.getElementById('HG-' + inputName).style.backgroundColor = "white";
}
}
if(check == 0){
for(i=0;i<inputs.length;i++){
var inputName = inputs[i].getAttribute('name');
var msg = document.getElementById('msg-' + inputName);
var store;
if(inputs[i].value == "yes" && inputs[i].checked == true){
msg.innerHTML = 'Correct Answer!';
document.getElementById('msg-' + inputName).style.color = "green";
document.getElementById('HG-' + inputName).style.backgroundColor = "white";
score++;
}
else if(inputs[i].value == "no" && inputs[i].checked == true){
msg.innerHTML = 'Wrong Answer!';
document.getElementById('msg-' + inputName).style.color = "red";
document.getElementById('hg-' + inputName).style.backgroundColor = "yellow";
document.getElementById('HG-' + inputName).style.backgroundColor = "white";
}
}
document.getElementById("score").innerHTML="Your score is:" + score;
return false;
}
return false;
}
</script>
</head>
<body>
<form name="myForm" onsubmit="return checkAnswers()" id="form">
<center><h1>QUESTIONS</h1></center>
<fieldset><br />
<div id="HG-one">
<span id="msg-one"></span>
<span>1.) It is a simple design language intended to simplify the process of maing web pages presentable.</span><br /> </div><br />
<input name="one" type="radio" value="yes" /><span id="hg-one">A. CSS</span><br />
<input name="one" type="radio" value="no" />B. HTML <br />
<input name="one" type="radio" value="no" />C. XML <br />
<input name="one" type="radio" value="no" />D. Bootstrap <br /><br />
</fieldset>
<br /><br />
<fieldset><br />
<div id="HG-two">
<span id="msg-two"></span>
<span>2.) Where is the Eiffel Tower located?</span><br /></div><br />
<input name="two" type="radio" value="no" />A. Miag ao<br />
<input name="two" type="radio" value="yes" /><span id="hg-two">B. Paris</span><br />
<input name="two" type="radio" value="no" />C. Madrid<br />
<input name="two" type="radio" value="no" />D. Korea<br />
</fieldset>
<br /><br />
<fieldset><br />
<div id="HG-three">
<span id="msg-three"></span>
<span>3.) Which country produces Proton cars?</span><br /></div><br />
<input name="three" type="radio" value="no" />A. Indonesia <br />
<input name="three" type="radio" value="yes" /><span id="hg-three">Malaysia</span><br />
<input name="three" type="radio" value="no" />C. Japan<br />
<input name="three" type="radio" value="no" />D. South Korea<br />
</fieldset>
<br /><br />
<fieldset><br />
<div id="HG-four">
<span id="msg-four"></span>
<span>4.) What is the name of the tallest structure ever built?</span><br /></div><br />
<input name="four" type="radio" value="no" />A. Grollo Tower <br />
<input name="four" type="radio" value="no" />B. CN Tower<br />
<input name="four" type="radio" value="yes" /><span id="hg-four">C. Burj Khalifa</span><br />
<input name="four" type="radio" value="no" />D. Taipei 101<br />
</fieldset>
<br /><br />
<fieldset><br />
<div id="HG-five">
<span id="msg-five"></span>
<span>5.) What type of creature is the children's animated character Pingu?</span><br /></div><br />
<input name="five" type="radio" value="no" />A. Porcupine <br />
<input name="five" type="radio" value="no" />B. Pony<br />
<input name="five" type="radio" value="no" />C. Pelican<br />
<input name="five" type="radio" value="yes" /><span id="hg-five">D. Penguin</span> <br />
</fieldset>
<br /><br />
<fieldset><br />
<div id="HG-six">
<span id="msg-six"></span>
<span>6.) What is the longest river in Pakistan?</span><br /></div><br />
<input name="six" type="radio" value="no" />A. Incara <br />
<input name="six" type="radio" value="no" />B. Indeema<br />
<input name="six" type="radio" value="no" />C. Indira<br />
<input name="six" type="radio" value="yes" /><span id="hg-six">D. Indus</span> <br />
</fieldset>
<br /><br />
<fieldset><br />
<div id="HG-seven">
<span id="msg-seven"></span>
<span>6.) What is the longest river in Pakistan?</span><br /></div><br />
<input name="seven" type="radio" value="no" />A. Incara <br />
<input name="seven" type="radio" value="no" />B. Indeema<br />
<input name="seven" type="radio" value="no" />C. Indira<br />
<input name="seven" type="radio" value="yes" /><span id="hg-seven">D. Indus</span> <br />
</fieldset>
<center><input type="submit" name='submit' value="Submit" /><br /><br />
<span id="score"></span><br />
</form>
</body>
</html>
我已将i += 4;更改为i += 3;