def count_slash_for(s):
    """
    Returns the number of times '/' appears in string s
    
    Parameter s: the string to search
    Precondition: s is a (possibly empty) string
    """
    # Accumulator
    count = 0
    
    # Loop variable
    for i in range(len(s)):
        if s[i] == '/':
            count= count + 1
    
    return count