Java uses the toUpperCase () and toLowerCase () methods of the string class to go to the case of a string

1. How to determine the case of the English alphabet:

 Packagecom.ldw.string; ImportJava.util.Scanner; /**   * @authorLDW e-mail: [email protected] *@versioncreated: April 28, 2015 12:47:26 * class description*/   Public classUppserorlower {Private StaticScanner Console;  Public Static voidMain (string[] args) {System.out.print ("Please enter a set of strings:"); Console=NewScanner (system.in); String Str=Console.nextline (); StringBuilder Upperstr=NewStringBuilder (); StringBuilder Lowerstr=NewStringBuilder (); inti = 0;  while(I <str.length ()) {              CharCHR =Str.charat (i); if(Character.isuppercase (CHR)) {upperstr.append (CHR); }Else if(Character.islowercase (CHR)) {lowerstr.append (CHR); } I++; } System.out.println ("Uppercase letters are:" +upperstr.tostring ()); System.out.println ("Lowercase letters are:" +lowerstr.tostring ()); }  }  

2.toUpperCase means that all English characters are converted to uppercase letters, such as:

String  cc = "aBc123". toUpperCase (); // The result is: ABC123. 

3.toLowerCase means that all English characters are converted to lowercase letters, such as:

String  cc = "ABc". toUpperCase (); // The result is: abc123. 

Note: These two methods are valid only for the English alphabet and have no effect on the remaining characters except A~z and A~z.

Java uses the toUpperCase () and toLowerCase () methods of the string class to go to the case of a string