??????????????
????(1)public String subString(int beginIndex);
????(2)public String subString(int beginIndex??int endIndex);//?????????????beginIndex?????endIndex-1???
??????????4λ????????дSyetem.out.println(*.subString()(*.length()-4));
???????????????滻
???????????
????(1)public String replace(char oldChar??char newChar);
????(2)public String replace(CharSequence target??CharSequence replacement);//???????etarget???????滻?replacement???У??????′?
????(3)public String replaceAll(String regex??String replacement);//???????????????????????
???????????????Сд?????
????(1)public String toLowerCase(Locale locale);
????(2)public String toLowerCase();
????(3)public String toupperCase(Locale locale);
????(4)public String toUpperCase();
?????????????????β???
????*.trim();
???????????????
????1?????????????????????
????public char[] toCharArray();
????2???????????????????????
????public String[] split(String regex);//regex ??????????
????3?????????????????????????
????(1)public static String valueOf(boolean b);
????(2)public static String valueOf(char c);
????(3)public static String valueOf(int i);
????(4)public static String valueOf(long i);
????(5)public static String valueOf(float f);
????(6)public static String valueOf(double d);
????(7)public static String valueOf(char[] data);
????(8)public static String valueOf(Object obj);
???????????????????????
???????????:
????public StringBuffer();
????public StringBuffer(int caoacity);
????StringBuffer???????????????
??????????????????????
????(1)public int length();
????(2)public int capacity();
????(3)public void setLength(int newLength);
??????????????????
??????String ???equals()????????????????
??????Object?е?equals()?????????????????????????????????????????????????String??????Object????????д??equals()??????????????????????????????
????????StringBuffer?????????дObject???equals()????????????????????????
????????????????????
????(1)??? public StringBuffer append(type t);
????(2)???? public StringBuffer insert(int offset??type t);//??offset???????????type???????
????????????????????
????(1)??? public StringBuffer reverse();
????(2)??? public StringBuffer delete(int start??int end);
?????塢????????????????е?洢???
????public void trimToSize();
????????StringBuffer???????String??
????public String toString();