char & pointers

[garrett85]

double get_number()
{
	char s[100];

	cin.getline(s, 99);
	if(strlen(s) == 0)
		return 0.0;
	return atof(s);
}

In the C++ book I'M reading chars are defined by char *variableName, but in the preceding code from the same book I see char s[100] without the * character? What have I missed?

In the following code I'M a little confused with the "convert" function. Is it working with the pointer s or the char s?

#include <iostream>
#include <string.h>
#include <ctype.h>
using namespace std;

void convert_to_upper(char *s);

int main()
{
	char s[100];

	cout<< "Enter string to convert and press ENTER: ";
	cin.getline(s, 99);

	convert_to_upper(s);
	cout<< "The converted string is:" << endl;
	cout<< s;

	system("pause");
	return 0;
}

void convert_to_upper(char *s)
{
	int i;
	int length = strlen(s);

	for(i = 0; i < length; i++)
		s[i] = toupper(s[i]);
}

[vlad from moscow]

The name of an array is converted to the pointer to its first element when it is used in expressions. So when you pass an array as an argument of a function it is converted to the pointer to its first element.