You are accepting parameters with same name nr
which is hiding global scope nr
.
Solution to your problem is remove nr
as parameter. So use function onLoadEvent()
instead of function onLoadEvent(nr)
题
Most of the action is in the function next
. The other functions are provided for context. The global variable tally
increments as it should when the right answer is selected. However the variable nr
is not incremented and I can't figure out way it is not.
You can see that I commented out that the next
function returned an object with tally
and nr
and assigned those values in the event listener. When I did it that way, it worked. But it should work the other way as well, right.
var nr = 0;
var tally = 0;
function onLoadEvent(nr) {
//alert('onload');
var quiz = document.getElementById('quiz');
var question = allQuestions[nr];
var next = quiz.lastElementChild;
var qHeader = "<h2>" + question.question + "</h2>";
var q = "";
for(var i=0;i<question.choices.length;i++){
q = q + '<p><label for="a' + i + '">' +
'<input type="radio" id="a' + i + '" name="q" value="' +
i + '">' + question.choices[i] + '</label></p>';
}
quiz.innerHTML = qHeader + q + next.outerHTML;
//next = document.getElementById('next');
}
function getChecked(){
var radios = document.getElementsByName('q');
var radio;
for(var i=0;i<radios.length;i++){
if(radios[i].checked){
radio = radios[i];
break;
}
}
return radio;
}
function next(nr){
if (getChecked() !== undefined) {
var answer = getChecked();
if(answer.value == allQuestions[nr].correctAnswer){
tally = tally + 1;
}
nr = nr + 1;
if (nr>=allQuestions.length){
alert("You got " + tally + " points!");
} else {
onLoadEvent(nr);
}
} else {
alert('You need to check a radio button');
}
//return {nr: nr, tally: tally};
}
var form = document.getElementById('quiz');
form.addEventListener('click', function(event){
if(event.target.id === 'next'){
next(nr);
//nr = obj.nr;
//tally = obj.tally;
} else if(event.target.id === 'prev'){}
}, false);
window.addEventListener('load', function(event){onLoadEvent(nr);}, false);
解决方案
You are accepting parameters with same name nr
which is hiding global scope nr
.
Solution to your problem is remove nr
as parameter. So use function onLoadEvent()
instead of function onLoadEvent(nr)