vb中mid,left,right函数的含义与用法?答:mid(str, n, len) 取出字符串str中第n个字符开始,长度为len位的字符串 sample: str = 'abcd' mid(str,2,3) = 'bcd'left(str,n) 取出字符串str中左边n位的字符 sample: str = 'abcd' left( str, 3) = 'abc'right(str,n) 取出字符串str中右边n位的字符 sample: str = 'abcd' right( str,...