Question

我的脚本导致浏览器冻结并要求我停止脚本。使用firebug我可以看到for循环无休止地循环而没有取得任何进展。这是循环：

for (var x = 1; x < 7; x++) {
    var y = x; //to stop the value of x being altered in the concat further down
    var questionidd = "mcq_question_id";
    console.log("1 = " + questionidd);
    var questionid = questionidd.concat(y); // mcq_question_id$ctr the question number
    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(y); // 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);
    }
}

更新 - 修正了！愚蠢的错误是最糟糕的

Answer 1

if (x = 1) {

应该是

if (x === 1) {

===运算符比较，而赋值运算符= 分配。很多人犯了这个错误。：）

当第一个循环运行时，它将x设置为零，并且无限地执行，直到进程终止。这就是循环不会停止的原因。

Answer 2

if (x = 1) {应为if (x === 1) {

考虑切换到能够捕获此类简单编程错误的IDE。

Answer 3

看起来你应该有“if（x == 1）”而不是“if（x = 1）”。

您的代码重复将x设置为值1，而不是检查它是否等于1。

For循环不会在Javascript中退出，无限循环

3 个答案: