String类中六种构造方法使用方法和作用
1.String s = new String("")；
2.String s = ""；
3.String s = new String(char数组);
4.String s = new String(char数组，起始下标，长度);
5.String s = new String(byte数组);
6.String s = new String(byt数组，起始下标，长度);
代码演示：
1.String s = new String("")；
String s = new String("abc"); System.out.println(s); //abc
2.String s = ""；
String s1 = "中国";
System.out.println(s1); //中国
3.String s = new String(char数组);
char [] c = new char[] {'a','b','c'};
String ss = new String(c);
System.out.println(ss); // a b c
4.String s = new String(char数组，起始下标，长度);
char [] c = new char[] {'a','d','d'};
String ss = new String(c,0,1);
System.out.println(ss); // a
5.String s = new String(byte数组);
byte [] b = new byte[] {48,49,99};
String sss = new String(b);
System.out.println(sss); // 0 1 c
6.String s = new String(byt数组，起始下标，长度);
byte [] b2 = new byte[] {48,49,50,66}; String sss1 = new String(b2,0,2); System.out.println(sss1); // 0 1
