Capturing the unknown elements in a deeply nested array

Question

Capturing the unknown elements in a deeply nested array

I'm trying to create a helper function that will return 0 if an element in a nested array is undefined. The issue I'm facing is that when the first index fails and returns undefined, the function should catch errors at subsequent indexes but it's not reaching them. What is the best approach to handle all errors in this situation?

function errorCatcher(arr){
  if (typeof(arr) == 'undefined') {
    return 0
 }

var some_var = errorCatcher(some_arr[0][1]) // even though some_arr[0] causes an error here, I want the helper function to catch all errors

javascript

Answer 1

Answer №1

It seems like you are attempting to achieve something similar to this concept. In this scenario, if arr is an empty array, it will fail at the second if statement. If arr is not an array for any reason, it will fail at the first if statement.

function get_val(arr, x, y){
   if (!arr || !Array.isArray(arr)) {
     return 0;
   }

   if (arr[x] === undefined || arr[x][y] === undefined) {
    return 0;
   }

   return arr[x][y];
}

var some_var = get_val(some_arr, 0, 1)

If you prefer to maintain the previous method, you need to handle the error accordingly.

function helper_check(arr){
  if (typeof(arr) == 'undefined') {
    return 0
 }

var some_var = 0;
try {
    some_var = helper_check(some_arr[0][1]);
}
catch(err) {//nothing to do here}

Another alternative, though less refined

function helper_check(arr){
  try {
     var val = eval(arr);
     if (typeof(val) == 'undefined') {
        return 0;
     }
     return val;
  catch(err) {
     return 0;
  }
 }

some_var = helper_check('some_arr[0][1]');

Answer 2

It seems like you are attempting to achieve something similar to this concept. In this scenario, if arr is an empty array, it will fail at the second if statement. If arr is not an array for any reason, it will fail at the first if statement.

function get_val(arr, x, y){
   if (!arr || !Array.isArray(arr)) {
     return 0;
   }

   if (arr[x] === undefined || arr[x][y] === undefined) {
    return 0;
   }

   return arr[x][y];
}

var some_var = get_val(some_arr, 0, 1)

If you prefer to maintain the previous method, you need to handle the error accordingly.

function helper_check(arr){
  if (typeof(arr) == 'undefined') {
    return 0
 }

var some_var = 0;
try {
    some_var = helper_check(some_arr[0][1]);
}
catch(err) {//nothing to do here}

Another alternative, though less refined

function helper_check(arr){
  try {
     var val = eval(arr);
     if (typeof(val) == 'undefined') {
        return 0;
     }
     return val;
  catch(err) {
     return 0;
  }
 }

some_var = helper_check('some_arr[0][1]');

Answer 3

Answer №2

While browsing through old questions, I stumbled upon this one which resonated with a problem I once faced. Here is my solution in case it could assist someone else encountering a similar issue.

typeof(arr) == 'undefined'

Initially, this method did not effectively capture the undefined state of [arr] within my code. I also experimented with the try/catch approach mentioned on https://www.w3schools.com/js/js_errors.asp, but encountered similar results.

The solution that actually worked for me was surprisingly simple - just check the length property of [arr].

if (arr.length < 1)

Depending on your preference for clarity, there are numerous other alternatives you can explore along this same line of reasoning.

Answer 4

While browsing through old questions, I stumbled upon this one which resonated with a problem I once faced. Here is my solution in case it could assist someone else encountering a similar issue.

typeof(arr) == 'undefined'

Initially, this method did not effectively capture the undefined state of [arr] within my code. I also experimented with the try/catch approach mentioned on https://www.w3schools.com/js/js_errors.asp, but encountered similar results.

The solution that actually worked for me was surprisingly simple - just check the length property of [arr].

if (arr.length < 1)

Depending on your preference for clarity, there are numerous other alternatives you can explore along this same line of reasoning.

Capturing the unknown elements in a deeply nested array

Answer №1

Answer №2

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