string

function int len(); //if str is "", str.len() is 0;

task putc(int i, string s);

task putc(int i, byte c);

function int getc(int i); // get the ascii value of ith character.

function string toupper(); // turn to upper case.

function string tolower(); // turn to lower case.

function int compare(string s); //

function int icompare(string s); // case insensitive compare.

function string substr(int i, int j);

function integer atoi(); // string s="123"; s.atoi() is 'd123.

function integer atohex();

function integer atooct();

function integer atobin();

function real atoreal();

task itoa(integer i); // int i=123; str.itoa(i) is "123"

task hextoa(integer i);

task octtoa(integer i);

task bintoa(integer i);

task realtoa(real i);