202002062025——『String関連』

 //1. String 
String(byte[] byte, int offset, int length);
String(char[] char, int offset, int count);
String(char[] value);

//2.  
char charAt(int index);
String substring(int beginIndex, int endIndex);
boolean startsWith(String prefix);
boolean startsWith(String prefix, int toOffset);

//3.  
int indexOf(String ch);// 
int indexOf(String ch, int startIndex);

//4. repalce
String replace(oldChar, newChar);
String replaceAll(Rex, replacement);
String replaceFirst(Rex, replacement);

//5.
 boolean isEmpty(); // length(); 0  -> true