在JSON中访问嵌套对象的正确方法是什么？

Question

If I understand correctly, list in this code is an array that consists of objects . I want to access temp in the main object and thought main.temp would do the trick, but I get an error message stating it's undefined. Alternatively I've tried list[1].main.temp . What is the correct way to access nested arrays like this?

Answer 1

What is the correct way to access nested arrays like this?

First of all these aren't nested arrays, but array of objects instead and in an array we access the items by index, and in objects we access them(entries) by keys.

So in your case list[0] is an object where list[0].dt is an entry and list[0].main is another entry of the object , so dt isn't at index 0 like you mentioned in your comment.

And to access all your array main.temp properties you need to loop throught the array elements using one of the Array built-in methods or just a for loop , because using static indexes in list[1].main.temp will just get the temp property of the firts element in the array and may throw an exception if this index is higner than the array.length .

This is how should be your code:

for(var i=0; i<list.length; i++){
    console.log(list[i].main.temp);
}