String is mean that group of sentences but it is used as integer value is it correct?

Question

>?php $str = "10"; $int = 20; $sum = $str + $int; echo ($sum);

Answer 1

Using var_dump($sum) we see that php convert for integer. If your code receive values of a html form its string. Then you needs convert for work with its. I think this for while.

I think that string is best define as set or group of characters.

I hope be helpful. Sorry my english.

Below my code of study this question:
https://code.sololearn.com/w6fxLJpsEE0q/?ref=app