我正试图从一系列答案中抓取3个随机答案并将它们存储到一个新数组中。 因此，选择答案的新数组几乎会有来自答案池的3个随机答案，以及正确的答案。我想我得到了什么，但唯一的问题是，如果已经使用了数组元素，我不知道如何跳过它，而是添加一个不同的元素。所以我最终在我的新数组中有重复项。
请在此处查看代码。
http://jsfiddle.net/oybojgzm/2/
var answerList = ["answer 1", "answer 2", "answer 3", "answer 4", "answer 5"];
var correctAnswer = "CORRECT!";
var selectedAnswers = [correctAnswer];
var randomNumber = 0;
function randomAnswer() {
if (selectedAnswers.length < 4) {
randomNumber = Math.floor((Math.random() * answerList.length) +
1) - 1;
for (i = 0; i < answerList.length; i++) {
if (answerList[randomNumber] === answerList[i]) {
randomNumber = Math.floor((Math.random() * answerList.length) +
1) - 1;
randomAnswer();
} else {
selectedAnswers.push(answerList[i]);
console.log(selectedAnswers);
randomNumber = Math.floor((Math.random() * answerList.length) +
1) - 1;
randomAnswer();
break;
}
}
}
}
randomAnswer();
答案 0 :(得分：1)
我建议使用shuffle函数，而不是多次从数组中选择一个随机索引。
NB。这假定maximumAnswers值始终为<=到answerList.length + 1
var answerList = ["answer 1", "answer 2", "answer 3", "answer 4", "answer 5"];
var correctAnswer = "CORRECT!";
var selectedAnswers = [];
var maximumAnswers = 4;
function generateAnswers() {
var tempAnswerList = shuffle(answerList); // lets create a clone of the answerList so we dont effect the original, and shuffle it
tempAnswerList = tempAnswerList.slice(0, maximumAnswers - 1); // - 1 cos we will be adding the correct answer
tempAnswerList.push(correctAnswer); // add correct answer to the
tempAnswerList = shuffle(tempAnswerList); // shuffle again so our correct answer isnt always last
console.log(tempAnswerList);
}
// from http://stackoverflow.com/questions/6274339/how-can-i-shuffle-an-array-in-javascript
function shuffle(o){ //v1.0
for(var j, x, i = o.length; i; j = Math.floor(Math.random() * i), x = o[--i], o[i] = o[j], o[j] = x);
return o;
};
generateAnswers();
<强> JSFIDDLE DEMO
答案 1 :(得分：0)
我更新了你的代码，因为我真的不明白你为什么要使用这么大的递归函数：
var answerList = ["answer 1","answer 2", "answer 3", "answer 4", "answer 5"];
var correctAnswer = "CORRECT!";
var selectedAnswers = [correctAnswer];
function wrong(answerList, number = 3) {
//number means the number of answers you want as a return, I took the default as being 3
var wrongAnswers = [];
//While the wrongAnswer array is not filled as it should be:
while (wrongAnswers.length < number && answerList.length > number) {
//Take a new random value
var random = Math.floor(Math.random() * answerList.length);
//and add it to our array if it isn't already in there (indexOf)
if (wrongAnswers.indexOf(answerList[random]) == -1)
wrongAnswers.push(answerList[random]);
}
//If the list of possible answers is shorter than the number of answers you need as a return, just return all the possible answers, else return the generated list
if (answerList.length <= number)
return answerList;
else
return wrongAnswers;
}
console.log(wrong(answerList));
答案 2 :(得分：0)
/*
Count: Number of answers to select
answerPool: Array containing the possible answers
selectedAnswers: Array that will be filled (possibly already containing elements)
*/
function selectRandomFromAndPushInto(count, answerPool, selectedAnswers) {
//Copy answerPool in case you want to reuse it for another call
answerPool = answerPool.slice();
//Iterate count times to select the random answers
for(var iteration = 0; iteration < count; iteration ++) {
//Find a random index in range 0 .. (answerPool.length - 1)
var index = Math.round(Math.random() * (answerPool.length - 1));
//Take the element at this index and push it into selectedAnswers
selectedAnswers.push(answerPool[index]);
//Remove the answer from answerPool, so that you won't select it again
answerPool.splice(index, 1);
}
//Return the resulting array
return selectedAnswers;
}
var answerPool = ["answer 1", "answer 2", "answer 3", "answer 4", "answer 5"];
var selectedAnswers = ["CORRECT!"];
console.log(selectRandomFromAndPushInto(3, answerPool, selectedAnswers));
产生类似的东西（使用node.js测试）：
[ 'CORRECT!', 'answer 3', 'answer 5', 'answer 4' ]
答案 3 :(得分：0)
以非常短的方式：
var answerList = ["answer 1", "answer 2", "answer 3", "answer 4", "answer 5"];
var correctAnswer = "CORRECT!";
var selectedAnswers = [correctAnswer];
var randomNumber = 0;
function randomAnswer() {
while(selectedAnswers.length < 4){
randomNumber = Math.floor(Math.random() * answerList.length);
if(!(selectedAnswers.indexOf(answerList[randomNumber])>-1))
selectedAnswers.push(answerList[randomNumber]);
}
}
randomAnswer();
答案 4 :(得分：0)
考虑从您使用它时可以测试的数组开始：
var answerList = ["answer 1", "answer 2", "answer 3", "answer 4", "answer 5"];
var correctAnswer = "CORRECT!";
var selectedAnswers = [];
var randomNumber, tmp, tm2, lng, i;
function randomAnswer() {
tmp=[];
tm2=0; //number of elements currently in the tmp array
lng=answerList.length; //save processing time by getting the length ONCE
while(tm2<3) { //loop til we get 3 numbers in the tmp array
randomNumber = Math.floor(Math.random() * lng); //array-index 0 thru (lng-1)
for(i=0; i<tm2; i++) //first random number always is acceptable
if(tmp[i]==randomNumber) //if array-index is in the tmp array
break; //stop looping/looking; prevents i from equalling tm2
if(i==tm2) //at end of UN-break'ed for loop, this would be true
tmp[tm2++]=randomNumber; //only different indices saved in tmp array
}//end of while loop, which gets another random number until 3 different ones are selected
//now put the correct answer somewhere, randomly, in the final array
randomNumber = Math.floor(Math.random() * 3); //array-index 0 thru 2
for(i=0; i<3; i++) { //we know there are 3 indices in the tmp array
if(i==randomNumber) //if our counter equals the random location for the answer
selectedAnswers.push(correctAnswer); //put the real answer into the output
selectedAnswers.push(answerList[tmp[i]]); //always put one of the other answers into the output
}
console.log(selectedAnswers);
}