我正在尝试使用 javascript 从我的 HTML 中的表单中获取隐藏输入的值。但是在尝试了几种不同的方法来获取值之后，它总是在控制台（萤火虫）中说变量为空..继承人的javascript：
var mcq_test = form.mcq_test.value;
console.log("mcqid=" + mcq_test)
var mcq_num_questions = form.mcq_num_questions.value;
console.log("totalquestions=" + mcq_num_questions)
var x = 1;
var send = [];
send.push("mcq_test=");
send.push(mcq_test);
console.log("Send: " + send);
// have commented out the bits below...just go through them carefully looking at the string functions, put them in the send += (SRING 1 + STRING 2 + ...) format
for (var x = 1; x <= mcq_num_questions; x++) {
var questionidd = "mcq_question_id";
console.log("1 = " + questionidd);
var questionid = questionidd.concat(x); // mcq_question_id$ctr the question numer
console.log("2 = " + questionid);
var mcqid = form.questionid.value; // the questions id on db
console.log("3 = " + mcqid);
var answerr = "mcq_question";
var answer = answerr.concat(x); // mcq_question$ctr the questions chosen answer
var chosenanswer = form.answer.value; // the answers value
console.log("4 = " + chosenanswer);
var amp = "&";
var equal = "=";
var questionide = questionid.concat(equal); // "mcq_question_id$ctr="
var questionida = amp.concat(questionide); // "&mcq_question_id$ctr="
var answere = amp.concat(answer,equal); // "&mcq_question$ctr="
if (x = 1) { send.push(questionide, mcqid, answere, chosenanswer); }
else {
send.push(questionida, mcqid, answere, chosenanswer);
}
}
安慰：
[04:08:00.328] TypeError: questionID is null
[04:08:00.327] My new function
[04:08:00.327] mcqid=566
[04:08:00.327] totalquestions=3
[04:08:00.327] Send: mcq_test=,566
[04:08:00.328] 1 = mcq_question_id
[04:08:00.328] 2 = mcq_question_id1
形式：
echo"<input type=\"hidden\" name=\"mcq_question_id$ctr\" id=\"mcq_question_id$ctr\" value=\"$questionID\" form=\"SubmitTest\" />";
- 更新
找到答案了！事实证明，您不能使用语法 document.getElementByID() 或 form.variable.value; 并在那里放一个变量，它必须是一个字符串或这样写：
form[variable].value;
我没有找到 getElementById 的等价物，但 form 方法对我有用。