11String class

String s1 = "abcd";          

String s2 = new String("ab cd");

//System.out.println(s1 == s2);

 

Returns the index for the 1 value, spaces are also considered

char c=s1.charAt(1);

System.out.println(c);

 

Contains

System.out.println(s1.contains("b"));

 

Whether it is xxx ending

System.out.println(s1.endsWith("c"));

 

The s into byte array

byte [] b=s1.getBytes();

for (byte d : b) {

System.out.println(d);

}

 

splice

System.out.println(s1.concat("aaaaaa"));

 

Returns the character in s appear first position

System.out.println(s1.indexOf(98));

System.out.println(s1.indexOf("c"));

//s1.intern();

 

System.out.println("---------------------");

 

Returns character index within this string of the last occurrence.

System.out.println(s1.lastIndexOf("a"));

 

length

System.out.println(s1.length());

 

replace

System.out.println(s1.replace("a", "b"));

 

 

 

Packet classification

String[] arr=s2.split(" ");

for (String bb : arr) {

System.out.println(bb);

}

 

Whether it is xx beginning

System.out.println(s1.startsWith("aa"));

 

Interception

System.out.println(s1.substring(2));

 

String variable group

char ccc[]= s1.toCharArray();

for (char d : ccc) {

System.out.println(d);

}

 

Variable capital

System.out.println(s1.toUpperCase());

 

Turn into a String

System.out.println(String.valueOf(false));