CPP

count characters in string

# count characters iterative
def count_chars(s)
  count = Hash.new(0)
  s.split("").each do |x|
    count[x] += 1
  end
  count
end

# count characters functional
s.chars.map {|c| [c, s.chars.count(c)] }.to_h

number of characters in string

std::string hello = "Hello";
int len = 1;
for(const char charac : hello)// Here the for loop take each character
                              // one by one and initialize it to charac.
                              // What happened in the for loop is
                              // for loop took the first character in hello
                              // and initialized it to charac(This was in the first loop)
                              // and so on until it processes all the characters
                              
{
++len;
}// Note : in any string variable there is always a space at the last(as below)
std::cout << "Number of characters is " << numofchars - 1;