Creating a string from a character array

[Milan]

Hi all,

I would like to use the strcmp - string compare function, however don't know how to create a string from character array. Standard way would be something like this:

char arr[ ] = "Hello World";
string str(arr);

However the compiler doesn't like the type string. Is there a way to create a string that I could use such as in the following example?

if(strcmp("Hello World",str) == 0)
{do something}

Regards

Milan

[Nguyen Hoan Hoang]

type string is a C++ class. It does not exists in C. A char array is a string already.

strcmp(arr, "what ever") == 0 ... that is how it's done. strcmp is a C function.

[Milan]

Let say I do this:

if (strcmp((char*)p_data, "rate") == 0)
{do something}

The function is executed in case I type all of these: r, ra, rat, rate

How can I avoid it? I wrote a comparison fuction that works however I expected strcmp to work as well.

Thanks for your entry.

Milan

[Nguyen Hoan Hoang]

the "do something" is executed only if the first 4 char of your p_data is equal to "rate"

[John]

Milan may have a point. An implementation of strcmp attributed to PJ Plauger is:

int strcmp (const char * s1, const char * s2)
{
    for(; *s1 == *s2; ++s1, ++s2)
        if(*s1 == 0)
            return 0;
    return *(unsigned char *)s1 < *(unsigned char *)s2 ? -1 : 1;
}

So if the null terminator of s1 is encountered before a difference is detected with s2, the strcmp will return 0. So, flipping the order of the arguments to strcmp might be one solution.

The web page I found this on is here: strcmp

[Nguyen Hoan Hoang]

ah! you're right. I've forgotten about it.