jQuery多维数组（动态键） - 无法设置未定义的属性

Question

感谢 Chad 的解决方案，但它现在似乎从数组中清除了值，这是控制台日志上的 foreach，它向您显示了我的情况（随后是更新功能的更新代码）：

timer.html:60 ------------------------------------
timer.html:57 0
timer.html:58 undefined
timer.html:57 1
timer.html:58 1.910
2timer.html:60 ------------------------------------
timer.html:57 0
timer.html:58 undefined
timer.html:57 1
timer.html:58 undefined
timer.html:57 2
timer.html:58 1.727
2timer.html:60 ------------------------------------
timer.html:57 0
timer.html:58 undefined
timer.html:57 1
timer.html:58 undefined
timer.html:57 2
timer.html:58 undefined
timer.html:57 3
timer.html:58 0.690
timer.html:60 ------------------------------------

==============================================

function updateLap(kartId){

  if (isNaN(driverLapNumber[kartId])) {
     //IF LAP NOT SET THEN THE KART ID NEEDS TO BE SET AS 0 AS IT IS THE START OF THE RACE
     window.driverLapNumber[kartId] = 0;  
  }

  //ADD ONE LAP TO THE KART ID
  driverLapNumber[kartId]++;

  //ADD LAP TIME FOR CURRENT LAP NUMBER  
  driverLapTimes[kartId] = [];
  driverLapTimes[kartId][driverLapNumber[kartId]] = window.lapTime;

   $.each(driverLapTimes , function( index, obj ) {
    $.each(obj, function( key, value ) {
        console.log(key);
        console.log(value);     
    });
    console.log("------------------------------------");
  });


  $(".lapTimes").prepend("kartId: "+kartId+" - "+window.lapTime+"<br>");

}

---

我想我可以把这归咎于 PHP，因为我目前编写它的方式是可能的，我需要帮助来纠正这个问题。

除了driverLapTimes 数组上的 SECOND 键外，一切都很好，我希望它输出如下内容：

driverLapNumber[999][1] = 6.666;
driverLapNumber[999][2] = 6.666;
driverLapNumber[999][3] = 6.666;
driverLapNumber[999][4] = 6.666;

但是 1,2,3,4 键出现以下控制台错误：

未捕获的类型错误：无法设置未定义的属性“1”

功能代码：

function updateLap(kartId){

  if (isNaN(driverLapNumber[kartId])) {
     window.driverLapNumber[kartId] = 0;  
  }

  //ADD ONE LAP TO THE KART ID
  driverLapNumber[kartId]++;

  //ADD LAP TIME FOR CURRENT LAP NUMBER
  driverLapTimes[kartId][driverLapNumber[kartId]] = window.lapTime;  

}

Answer 1

在这种情况下，很可能数组项尚未声明为新数组。试试这个：

function updateLap(kartId){



if (isNaN(driverLapNumber[kartId])) {
     window.driverLapNumber[kartId] = 0;  
  }

  //ADD ONE LAP TO THE KART ID
  driverLapNumber[kartId]++;

  //ADD LAP TIME FOR CURRENT LAP NUMBER
  if(!driverLapTimes[kartId]){
       driverLapTimes[kartId] = [];
  }
  driverLapTimes[kartId][driverLapNumber[kartId]] = window.lapTime;  

}

当然，您总是可以将声明放在此循环之外，方法是先创建一个方法来构造您的数组。

Answer 2

试试下面告诉我

var a = new Array();
a[0]= new Array();
a[0].push(1);
a[0].push(2);
a[0].push(3);

console.log(a[0][0]);
console.log(a[0][1]);
console.log(a[0][2]);