Capitalising first letter of Strings

[ca9mbu]

OK, I'm a newbie C++ programmer. I know there are two ways of storing strings. Either for example, char name[10] or string name (if you include string.h). To capitalise the first letter of any given string in the first example would be easy since you just need to access name[0], but what about in the second example? Does anyone know of any downloadable C++ function references - preferably easy to search/navigate - I'm using the DJGPP compiler and Info aint the easiest thing to get around!

Thanks in advance

Matt

#include <string>
#include <iostream>

using namespace std;

int main()
{
	string str = "hello world";
	int l = str.length() - 1;
	char *first = (char*)str.substr(0,1).c_str();
	if(first[0] >= 'a' && first[0] <= 'z')
		first[0] = first[0] - 32;
	String back = str.substr(1, l);
	str = first;
	str += back;
	cout << str;
	return 0;
}

[ca9mbu]

Actually I found an answer yesterday going through some Borland help files:

#include <string>
#include <iostream>

string name;
cout << "Please enter your first name";
cin >> name;

char initial;
initial = name.at(0); // retrieves first character

If (initial >='a' && initial <='z')
    name.replace(0,1,intital - 32)

cout >> name;

Thanks anyway.

Matt

[Jop]

I believe it would be faster to Xor the character with the value 0x20 (2^5), this will (i believe it's called) shift (I mean witch between 1 and 0) the 6th bit, which will turn the character either Uppercase if it was Lowercase, and Lowercase to uppercase if it was lowercase..
confused yet?

#include <string>
#include <iostream>

string name;
cout << "Please enter your first name";
cin >> name;

char initial;
initial = name.at(0); // retrieves first character

If (initial >='a' && initial <='z')
    name.replace(0,1,intital ^ 0x20) //I believe ^ is for Xor?

cout >> name;

would be slightly faster/cooler I think

Shifting isn't quite the same thing.

Bit Shift Left:

int x = 5; //5 in binary = 101
x = x << 1; //x now equals 10, 10 in binary is 1010

Bit Shift Right:

int x = 5; //5 in binary = 101
x = x >> 1; //x now equals 2, 2 in binary is 10

shift left = add a bit to the end, the bit is always 0.
shift right = remove a bit.

You can also shift different numbers of bits:

int x = 5; //5 in binary = 101
x = x << 2; //x now equals 20, 20 in binary is 10100

int x = 5; //5 in binary = 101
x = x >> 2; //x now equals 1, 1 in binary is 1

[ca9mbu]

Thanks for the replies, the help is greatly appreciated. Firstly Jop, I only need to swap from lower to uppercase and not the other way around as well. Secondly, in the code segment i gave you for my solution to it I called the function .at(0) once putting the result in a variable. Instead of doing this I could of course have repeated the function call everywhere where I used the name of the variable. This lead me to thinking about performance/optimising programs in terms of a) number of instructions carried out and b) memory usage. Are there any freeware programs that can tell me what the memory usage/processor time taken of my programs is?

[Jop]

Thanks Dennis, I knew it wasn't shifting what I meant

btw: if you use Copy & paste, be sure to modify the parts you copied

x = x << 2; //x now equals 20, 10 in binary is 10100 
...
x = x >> 2; //x now equals 1, 2 in binary is 1

thanks Jop. It's all fixed now.