Javascript multidimentional数组未定义的对象错误

Question

I am trying to make a two dimensional array out of two one dimentional arrays with this code:

  var PassAssoArr = new Array();
  for(k in PassPourcentNames) {
    PassAssoArr[k][0] = PassPourcentNames[k]
    PassAssoArr[k][1] = PassPourcentValue[k]
  }

However, I get the error message: " 'undefined' is null or not an object " and it points to the first line after the for statement. PassPourcentNames and PassPourcentValue have the same number of elements and none of the values are null. The first one contain strings and the second one integers.

Any help is greatly apreciated.

Answer 1

First define PassAssoArr[k] = []; before assigning to [0] and [1] .

Answer 2

Javascript does not support true multi-dimensional arrays.

You're trying to use nested arrays without creating the inner arrays.

You need to put an array into each element of the outer PassAssoArr :

PassAssoArr[index] = [];   //Empty array literal

Answer 3

你只定义了PassAssoArr的一个维度 - 你需要设置PassAssoArr [k] = new Array（）;

Answer 4

  var PassAssoArr = new Array();
  for(k in PassPourcentNames) {
    PassAssoArr[k] = new Array();
    PassAssoArr[k][0] = PassPourcentNames[k]
    PassAssoArr[k][1] = PassPourcentValue[k]
  }

Also instead of new Array() you can use []

  var PassAssoArr = [];
  for(k in PassPourcentNames) {
    PassAssoArr[k] = [];
    PassAssoArr[k][0] = PassPourcentNames[k]
    PassAssoArr[k][1] = PassPourcentValue[k]
  }

I believe this is actually faster in most JS engines.

Answer 5

试着做：

PassAssoArr[k] = new Array(PassPourcentNames[k], PassPourcentValue[k]);