（1）func HasPrefix(s, prefix string) bool
Determining whether a prefix string string s prefix;
（2）func HasSuffix(s, suffix string) bool
Determining whether there is a suffix string s suffix string;
（3）func Contains(s, substr string) bool
Determining whether the character string contains the substring s substr;
（4）func Count(s, sep string) int
Returns a string will not be repeated a few sep s substring;
（5）func Index(s, sep string) int
Returns the string s neutron sep first occurrence of the string; -1 does not exist;
（6）func ToLower(s string) string
Returns a copy of string s small letter;
（7）func ToUpper(s string) string
S turn returns the string copy uppercase;
（8）func Repeat(s string, count int) string
Returns the count of the string of series string s;
（9）func Replace(s, old, new string, n int) string
S n before returning the string will not repeat old to new replacement string substring new sub-string; n <0 substring replace all old;
（10）func Trim(s string, cutset string) string
Returns the string s front end to remove all substrings strings cutset;
（11）func TrimSpace(s string) string
Returns the string s before and after removing the end blank characters (unicode.IsSpace specified) of the string;
（12）func TrimLeft(s string, cutset string) string
Returns the string s distal remove all substrings strings cutset;
（13）func TrimRight(s string, cutset string) string
Returns the string s to remove the rear end of the string cutset all substrings;
（14）func TrimPrefix(s, prefix string) string
Returns the string s to remove the prefix string prefix substring;
（15）func TrimSuffix(s, suffix string) string
Returns the string s removed for suffix string substring;
（16）func Fields(s string) []string
Returns the string s with one or more blank ( a plurality of strings slices unicode.IsSpace) character segmentation; blank or empty string returns an empty string sections;
（17）func Split(s, sep string) []string
Returns a string by the string s slice is a substring sep divided; sep when an empty string, the string s is divided into sections each of yard unicode value;
（18）func Join(a []string, sep string) string
Returns a string to the string sections connected sep substring;
（19）func NewReader(s string) *Reader
Reader create a reading pointer data from a string S;