Comparing Letters to one another

string MyVariable = "d";

If (MyVariable < "f")
{
  // do this
}
else if (MyVariable < "t")
{
  // do this
}

list variable_letter = ["e"];
list set_letter = ["c"];
list alphabet = ["a", "b", "c", "d", "e", "f", "g", "h", "i"];

default {
touch_start(integer num_detected) {
	integer variable = llListFindList(alphabet, variable_letter); 
	integer set = llListFindList(alphabet, set_letter);

	if (variable > set)
	llOwnerSay((string)variable_letter + " comes after " + (string)set_letter);

	if (variable<set)
	llOwnerSay((string)variable_letter + " comes before " + (string)set_letter);

	if (variable == set)
	llOwnerSay("They are both the same");
		
    }
}

string variable_letter = "c";
string set_letter = "j";
string alpha_numeric = "abcdefghijklmnopqrstuvwxyz";

default
{
    touch_start(integer num_detected)
    {
        integer variable = llSubStringIndex(alpha_numeric, variable_letter);
        integer set = llSubStringIndex(alpha_numeric, set_letter);
    
        if (variable > set)
        {
            llOwnerSay((string)variable_letter + " comes after " + (string)set_letter);
        }
        if (variable<set)
        {
            llOwnerSay((string)variable_letter + " comes before " + (string)set_letter);
        }
        if (variable == set)
        {
            llOwnerSay("They are both the same");
        }
    }
} 

//
// String Compare functions for LSL.
//
//
string characters = " !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~";


integer STRINVALID = -99999;
integer STREQUAL = 0;
integer STRLESSTHAN = -1;
integer STRGREATERTHAN = 1;

integer strncmp(string a, string b,integer len)
{
    // compares two strings character by character.
    // return as soon as there is a difference
    integer result = STREQUAL;
    if(a != b)
    {
        integer index = 0;
        do
        {
            string chara = llGetSubString(a,index,index);
            string charb = llGetSubString(b,index,index);
            
            integer posa = llSubStringIndex(characters,chara);
            integer posb = llSubStringIndex(characters,charb);
            
            if((posa >= 0) && (posb >= 0))
            {
                result = posa - posb;
            }
            else if(posa >= 0)
            {
                result = STRGREATERTHAN;
            }
            else if(posb >= 0)
            {
                result = STRLESSTHAN;
            }
            
            if(result != STREQUAL) index = len;
            ++index;
                
        }
        while(index < len);
    }
    
    // limit to constant values
    if(result < STRLESSTHAN)result = STRLESSTHAN;
    else if(result > STRGREATERTHAN)result = STRGREATERTHAN;
        
    return result;
}

integer strnicmp(string a, string b,integer len)
{
    string lca = llToLower(a);
    string lcb = llToLower(b);
    return strncmp(lca,lcb,len);
}

integer strcmp(string a, string b)
{
    integer lena = llStringLength(a);
    integer lenb = llStringLength(b);
    integer result = STRINVALID;
    if(lena < lenb) 
        result =  strncmp(a,b,lena);
    else 
        result =  strncmp(a,b,lenb);
    
    return result;
}


integer stricmp(string a, string b)
{
    integer lena = llStringLength(a);
    integer lenb = llStringLength(b);
    string lca = llToLower(a);
    string lcb = llToLower(b);
    integer result = STRINVALID;
    if(lena < lenb) 
        result =  strncmp(lca,lcb,lena);
    else 
        result =  strncmp(lca,lcb,lenb);
    
    return result;
}


default
{
    state_entry()
    {
        string a = "ABCDEF[]";
        string b = "abcdef[]";
        integer result = strcmp(a,b);
        integer result2 = strncmp(a,b,3);
        integer result3 = stricmp(a,b);
        integer result4 = strnicmp(a,b,4);
        llOwnerSay("result =  " + (string)result);
        llOwnerSay("result2 =  " + (string)result2);
        llOwnerSay("result3 =  " + (string)result3);
        llOwnerSay("result4 =  " + (string)result4);
    }
}