What s[i]-'0' does

It seems that s is a character array or a pointer to the first 
element of a character array. And element s[i] contains a character
that represents a digit as for example '5' . To convert this character
that for example in ASCII has internal code equal to 53 
(while internal code of character '0' is 48) there is used expression

s[i] -'0'
that is equivalent to

53 - 48
and equal to number 5

What s[i]-'0' does

    '0' - 48
    '1' - 49
    '2' - 50
    '3' - 51
    '4' - 52
    '5' - 53
    '6' - 54
    '7' - 55
    '8' - 56
    '9' - 57

Source: stackoverflow.com

Similar codes

0 vote156 views1 answer
What type is this c++
C++
3 votes154 views1 answer
Initialzing a 2d vector in cpp
C++
0 vote175 views1 answer
Memset array bool
C++
35 votes181 views6 answers
Ellipsis
C++
0 vote172 views1 answer
Distructor of the node of the link list
C++
5 votes169 views3 answers
Cpp random number in range
C++
0 vote174 views1 answer
Get bitshift to wrap c++
C++
1 vote157 views1 answer
Const char to string
C++
-1 vote176 views1 answer
How to print items in arduino
C++
0 vote129 views1 answer
Replace a substring with another string in c++
C++