Various methods of Java String class
        
      
      
   
      
Method related to string inspection
| Method | 
operation | 
Argument type | 
Return type | 
| equals | 
Check if the contents are equal | 
String | 
boolean | 
| equalsIgnoreCase | 
Check if the content is equal, ignoring case | 
String | 
boolean | 
| length | 
Check the length of the string | 
String | 
int | 
| isEmpty | 
Check if it is an empty string | 
String | 
int | 
Methods for string search
| Method | 
operation | 
Argument type | 
Return type | 
| contains | 
Find out if it contains a string | 
String | 
boolean | 
| startsWith | 
Find out if it starts with the specified string | 
String | 
boolean | 
| endsWith | 
Checks if it ends with the specified string | 
String | 
boolean | 
| indexOf | 
Find out where the specified character or string first appears | 
String | 
int | 
| lastIndexOf | 
Search from the back for the specified character or string to find out where it first appears | 
String | 
int | 
Method related to string clipping
| Method | 
operation | 
Argument type | 
Return type | 
| charAt | 
Cut out one character at the specified position | 
int | 
String | 
| startsWith | 
Checks if it starts with the specified string | 
String | 
boolean | 
| endsWith | 
Checks if it ends with the specified string | 
String | 
boolean | 
| indexOf | 
Find out where the specified character or string first appears | 
String | 
int | 
| lastIndexOf | 
Search from the back for the specified character or string to find out where it first appears | 
String | 
int | 
Methods for string conversion
| Method | 
operation | 
Argument type | 
Return type | 
| toLowerCase | 
Convert uppercase to lowercase | 
String | 
String | 
| toUpperCase | 
Convert uppercase to lowercase | 
String | 
 | 
| trim | 
Remove leading and trailing whitespace | 
String | 
 | 
| replace | 
Replace with the specified string | 
String,String | 
String | 
| reverse | 
Invert the specified string | 
String | 
 | 
References
Java introductory practice that you can understand clearly