PHP sum last 6 digit from substring

Question

I'm trying to adding all numbers from last 6 digit from substr(). Let say the number is 19283774616, I'm trying to have result from this: 7+7+4+6+1+6 = ?. Here is my current code

public function accountHash($accountNumber)
{
    $result = 0;
    $accountNumber = substr($accountNumber, -6);

    for($i=0; $i<=strlen($accountNumber); $i++) {
        $result += substr($accountNumber, $i, 1); // A non-numeric value encountered here
    }

    echo $result;

}

From the function above, "A non-numeric value encountered" error occurred. Need suggestion on how to do this. Thank you

You already know how to do `substr($accountNumber, -6)`, so you just need to split and sum. — mickmackusa, Jul 11 '22 at 22:13

Anatoliy R · Accepted Answer · 2019-11-01T00:22:55.567

0

You attempt to get more characters than string contains. Replace "<=" with "<" in your condition expression, i.e. change:

for($i=0; $i<=strlen($accountNumber); $i++) {

to

for($i=0; $i<strlen($accountNumber); $i++) {

edited Nov 01 '19 at 00:22

answered Oct 31 '19 at 23:48

Anatoliy R

1,749
2
14
20

Um, I don't see what the difference is between both lines of code. Or, have I missed something? Oh wait... as I was typing this, I kept staring at what was different and then it suddenly hit me after about a minute. It was the added `=` (equal) sign. *That* should have been part of the answer. Others might also not pick it up so quickly. Please edit it. My comment stands to not be reliable later on, as it could disappear without any advance notice. – Funk Forty Niner Nov 01 '19 at 00:17
Edited as per @FunkFortyNiner concern – Anatoliy R Nov 01 '19 at 00:24

score 0 · Answer 2 · answered Nov 01 '19 at 00:36

0

You need to use < instead of <= in your for loop.

And you can do it a more simple way,

$result = 0;
for($i = 0; $i < 6; $i++){
    $result += $string[-$i];
}

answered Nov 01 '19 at 00:36

LF00

27,015
29
156
295

score 0 · Answer 3 · answered Nov 01 '19 at 10:52

0

An alternative method without loops (or error checking, for what it's worth):

function accountHash($accountNumber)
{
    return array_sum(
        preg_split('//u', mb_substr($accountNumber, -6), null, PREG_SPLIT_NO_EMPTY)
    );
}

Demo

answered Nov 01 '19 at 10:52

Álvaro González

142,137
41
261
360

PHP sum last 6 digit from substring

3 Answers3