javascript 中的动态多维数组 - 计数不起作用

Question

I need a 3 dimensional array to count up - it needs to grow dynamically. It consists of index, string1 and string2.

This outputs exactly, what I want (for a single loop, since the array is just hardcoded to index 0)

   var otr_entries=[[0,"",""]];
   var otr_entries_count=0;

   some_working_for_loop()
   {
      if(is_important_value_to_save())
      {
         //otr_entries_count=otr_entries_count+1;
         otr_entries[otr_entries_count][1]=xx[i].previousElementSibling.innerHTML;
         otr_entries[otr_entries_count][2]=xx[i].innerHTML;
         window.alert(otr_entries[otr_entries_count][1]); // Expected output
         window.alert(otr_entries[otr_entries_count][2]); // Expected output
      }
   }

but when I replace otr_entries[0][2] with otr_entries[otr_entries_count][2] the script suddenly fails, if the count is not 0. That means, that the array is not just growing. So how can this be archived?

   var otr_entries=[[0,"",""]];
   var otr_entries_count=0;

   just_some_perfectly_working_for_loop(;;)
   {
      if(is_important_value_to_save())
      {
         otr_entries_count=otr_entries_count+1; // Counting up breaks the code
         otr_entries[otr_entries_count][1]=xx[i].previousElementSibling.innerHTML;
         otr_entries[otr_entries_count][2]=xx[i].innerHTML;
         window.alert(otr_entries[otr_entries_count][1]); // No output, script totally stops
         window.alert(otr_entries[otr_entries_count][2]); // No output, script totally stops
      }
   }

EDIT:

This is my solution, thanks to peters help. Works perfectly fine.

   var otr_entries=[];
   var otr_entries_count=-1;

   some_working_for_loop()
   {
      if(is_important_value_to_save())
      {
         otr_entries_count=otr_entries_count+1;
         otr_entries.push(otr_entries_count,xx[i].previousElementSibling.innerHTML,xx[i].innerHTML)
         window.alert(otr_entries[otr_entries_count][1]); // Expected output
         window.alert(otr_entries[otr_entries_count][2]); // Expected output
      }
   }

Answer 1

You're just incrementing the counter before you add new item in the array. The solution is to move the counter incrementing line at the end:

This worked for me

const otr_entries=[[0,"",""]];
const otr_entries_count=0;

for(const entry of otr_entries) {
    // condition
    if(true) {
        otr_entries[otr_entries_count][1]='something';
        otr_entries[otr_entries_count][2]='something else'
        window.alert(otr_entries[otr_entries_count][1]);
        window.alert(otr_entries[otr_entries_count][2]);
        otr_entries_count+=1;
    }
}

Answer 2

If in the loop you're trying to add to the array you need to do otr_entries.push([count,"something","something2"]).

Also, if you're adding to the array you shouldn't be using that same array as your loop control.