Thread: best way to base condition on string

What is the best way to do a "switch" equivelant for a string.

I have been using

if ( strncmp( string1, string2, s ) == 0 )
else if ( strncmp( string1, string3, s ) == 0 )
else if ( strncmp( string1, string4, s ) == 0 )
etc


Is there a more efficient way of doing this?

nope - that's how it's done. of course, placing the strings in an array might clean up the code quite a bit and reduce the size of the program somewhat.

ok, thanks I just wasnt sure if I was doing something stupid or not.

Originally Posted by Kinasz

What is the best way to do a "switch" equivelant for a string.

I have been using

if ( strncmp( string1, string2, s ) == 0 )
else if ( strncmp( string1, string3, s ) == 0 )
else if ( strncmp( string1, string4, s ) == 0 )

Is there a more efficient way of doing this?

For less than, say 20 strings, no. For 20 to 100, a linear search is fine. For more strings, a bsearch() in a sorted array is probably more efficient. For huge number of complete strings (strcmp()) some hashed-based code is probably the fastet way to do it.

sweet I will look into it

Code:

lowercaseyourstring( whatever );
switch( *whatever )
{
    case 'a':
        if( !strcmp( whatever, "aardvark" )
        {
        }
        else
        if( !strcmp( whatever, "apple" )
        {
        }
        else
        if( !strcmp( whatever, "anything" )
        {
        }
        ...
    break;
    case 'b':
        if( !strcmp( whatever, "boy" )
        {
        }
        else
        ...
    break;
    ...
}

I suppose it all depends on exactly what you're doing...

Quzah.

Originally Posted by quzah

Code:

lowercaseyourstring( whatever );
switch( *whatever )
{
    case 'a':
        if( !strcmp( whatever, "aardvark" )
        {
        }
        else
    ...
}

That's a smart compromize. I'll try to recall it. Thanks.