Currently i have an array $newArr with some elements as shown in picture below. How do I know the last digit of the array index (highlighted in yellow)?
This is important because, if later I wanted to insert a new record into this $newArr array, I could just
$newArr[$the_variable_that_holds_the_last_digit + 1] = ['foo', 'bar']; otherwise the whole array overwrite if
$newArr = ['foo', 'bar']; I think you are looking for end pointer
$array = array( 'a' => 1, 'b' => 2, 'c' => 3, ); end($array); // it will point to last key $key = key($array); // get the last key using `key` 
$key = c.Assuming you have the numerically indexed array, the last index on your array is :
$last_index = count($newArr) -1; if However your keys are not sequential, you can do this:
end($newArr); $last_key = key($newArr); 
['0' => ..., '1' => ..., '3' => ...].
Assuming you have the numerically indexed array. the solution is for numerical keys only.
0,1,3,7 are numeric, they are just NOT consecutive. count = 4 but Highest index value = 7I think you can try this
$array = end($newArr); $last_index = key($array);//Its display last key of array For more details, please follow this link.
key will only provide the current key, i.e first, you need to move pointer to last then access the keyend() returns the last element of the array.If the only reason is to not overwrite the values you can use [] which means add new value.
$arr = [1,2,3,4]; var_dump($arr); // incorrect way: $arr = [1,2]; var_dump($arr); //correct way $arr = [1,2,3,4]; $arr[] = [1,2]; var_dump($arr); See here for output: https://3v4l.org/ZTg28
The "correct way" will in the example above input a new array in the array.
If you want to add only the values you need to insert them one at the time.
$arr[] = 1; $arr[] = 2; 
$newArr[] = ['foo', 'bar'];orarray_push($newArr, ['foo', 'bar']);