How to take the units of a two-digit number

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1

I need to get the units of a two-digit number with PHP.

example: 

$num = 25;
$dig1 = 2;
$dig2 = 5;
php

  • You want to sort the numbers by digits, that?

  • I just want to take their unit, the first digit, and the second digit, and create a number by part, as you see in the example

4 answers

3


To get the unit, just calculate the rest of the division by 10:

$num = 25;
echo $num % 10; // Imprime 5

And for the ten, just take the entire part of the division by 10:

$num = 25;
echo intdiv($num, 10); // Imprime 2

The same works for negative values:

$num = -25;
echo intdiv($num, 10) . PHP_EOL; // Imprime -2
echo $num % 10 . PHP_EOL; // Imprime -5

See working on Ideone.

PHP 5

As the function intdiv only introduced in PHP version 7, an alternative to PHP 5 is to use the function round:

echo round($num/10, 0, PHP_ROUND_HALF_DOWN);

The first value refers to the value to be rounded; the second refers to the number of decimal places and the third if it should be rounded down. In this way, I would return 2 to $num = 25 and -2 to $num = -25.

  • the function intdiv() is not working here, it is saying that it does not exist

  • @Ricardoparizsilva, sorry, this function was only introduced in PHP version 7. I will edit the answer with an alternative to PHP 5.

  • All right, thank you

2

In php every string can be considered an array of characters and it is possible to cast from int to string, so you can get the digits of a number like this

In PHP 7

$num = 25;
$dig1 = ((string)abs($num))[0];
$dig2 = ((string)abs($num))[1];

In PHP >= 5.4

$num = 25;
$dig1 = strval(abs($num))[0];
$dig2 = strval(abs($num))[1];

  • There’s also the problem that $num is negative. Position 0 of string would be the sign of least.

  • Really, I think it was not a good solution, I fixed to at least not have this problem

  • for my case it works, since valid if the number is negative before doing operations with it

1

Divide by 10 and take the rest of the division.

$num = 25;
$unidades = 25 % 10; // retorna 5

1

You can use the function str_split() php

$array = str_split($num);

  • If $num is negative, the result loses meaning.

  • If in your case it’s allowed, you can always do the following $array = str_split(abs($num)); So will the Absolute value of $num

  • In this case it would result in 2 and 5 (positive), which mathematically does not make sense. If the input is only positive, it is a solution, but if it can be negative, it is best to do it by mathematical operations.

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