(1) 程序可以实现巨型整数、长整型数、字符串之间的相加减

(2) 程序可以实现巨型整数、长整型数、字符串之间的大小对比，如大于、小于、等于、不等于、不大于、不小于运算的对比。

-(1) program can achieve huge integer, long integer, a string of phase between the addition and subtraction (2) program can achieve huge integer, long integer, a string comparison between the size, such as greater than, less than is equal to, not equal, not more than, not less than the comparison operation.