How to get the exact value of the last array index in PHP?

Question

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'];

Many answers had been given. I just want to add that if you want to add a value at the end of your array, you can just do `$newArr[] = ['foo', 'bar'];` or `array_push($newArr, ['foo', 'bar']);` — Kévin Bibollet, Aug 10 '17 at 13:28

score 3 · Accepted Answer · answered Aug 10 '17 at 13:24

3

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`

answered Aug 10 '17 at 13:24

Jigar Shah

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why does key($newArr) returns 0? It suppose to be 2, no? – begineeeerrrr Aug 11 '17 at 01:55
yes, it should return 2 if everything going proper, if you paste my example it will return `$key` = `c`. – Jigar Shah Aug 11 '17 at 04:36

score 2 · Answer 2 · edited Jun 12 '21 at 22:55

2

I 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.

edited Jun 12 '21 at 22:55

halfer

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answered Aug 10 '17 at 13:22

AddWeb Solution Pvt Ltd

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`key` will only provide the current key, i.e first, you need to move pointer to last then access the key – Jigar Shah Aug 10 '17 at 13:26
1

No its not the answer, because the OP wants a key of the last element, NOT the last element. `end()` returns the last element of the array. – Amit Joshi Aug 10 '17 at 13:29
why does key($newArr) returns 0? It suppose to be 2, no? – begineeeerrrr Aug 11 '17 at 01:54
@begineeeerrrr When you should only use key($newArr) then this function return current key only but you should use as per my answer then return last key of array. – AddWeb Solution Pvt Ltd Aug 11 '17 at 07:54

Amit Joshi · Answer 3 · 2017-08-10T13:36:11.730

2

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);

edited Aug 10 '17 at 13:36

answered Aug 10 '17 at 13:23

Amit Joshi

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Not good if your array looks like this: `['0' => ..., '1' => ..., '3' => ...]`. – Kévin Bibollet Aug 10 '17 at 13:24
Thats why I said `Assuming you have the numerically indexed array`. the solution is for numerical keys only. – Amit Joshi Aug 10 '17 at 13:26
1

`0,1,3,7` are numeric, they are just NOT consecutive. `count = 4` but `Highest index value = 7` – RiggsFolly Aug 10 '17 at 13:31
OK I edited the answer. Check it out and let me know if that works. – Amit Joshi Aug 10 '17 at 13:39
why does key($newArr) returns 0? It suppose to be 2, no? – begineeeerrrr Aug 11 '17 at 01:54
if you call `key($newArray)` without calling `end($newArray)` first then the key of the first array element (which is `0`) will be returned. You will have to call `end()` to take the pointer of the array to its last element. – Amit Joshi Aug 11 '17 at 02:51

score 1 · Answer 4 · answered Aug 10 '17 at 13:41

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;

How to get the exact value of the last array index in PHP?

4 Answers4