[java] Converting to upper and lower case in Java

I want to convert the first character of a string to Uppercase and the rest of the characters to lowercase. How can I do it?

Example:

String inputval="ABCb" OR "a123BC_DET" or "aBcd"
String outputval="Abcb" or "A123bc_det" or "Abcd"

This question is related to java string

The answer is


String a = "ABCD"

using this

a.toLowerCase();

all letters will convert to simple, "abcd"
using this

a.toUpperCase()

all letters will convert to Capital, "ABCD"

this conver first letter to capital:

a.substring(0,1).toUpperCase()

this conver other letter Simple

a.substring(1).toLowerCase();

we can get sum of these two

a.substring(0,1).toUpperCase() + a.substring(1).toLowerCase();

result = "Abcd"


I consider this simpler than any prior correct answer. I'll also throw in javadoc. :-)

/**
 * Converts the given string to title case, where the first
 * letter is capitalized and the rest of the string is in
 * lower case.
 * 
 * @param s a string with unknown capitalization
 * @return a title-case version of the string
 */
public static String toTitleCase(String s)
{
    if (s.isEmpty())
    {
        return s;
    }
    return s.substring(0, 1).toUpperCase() + s.substring(1).toLowerCase();
}

Strings of length 1 do not needed to be treated as a special case because s.substring(1) returns the empty string when s has length 1.


String inputval="ABCb";
String result = inputval.substring(0,1).toUpperCase() + inputval.substring(1).toLowerCase();

Would change "ABCb" to "Abcb"


WordUtils.capitalizeFully(str) from apache commons-lang has the exact semantics as required.


/* This code is just for convert a single uppercase character to lowercase 
character & vice versa.................*/

/* This code is made without java library function, and also uses run time input...*/



import java.util.Scanner;

class CaseConvert {
char c;
void input(){
//@SuppressWarnings("resource")  //only eclipse users..
Scanner in =new Scanner(System.in);  //for Run time input
System.out.print("\n Enter Any Character :");
c=in.next().charAt(0);     // input a single character
}
void convert(){
if(c>=65 && c<=90){
    c=(char) (c+32);
    System.out.print("Converted to Lowercase :"+c);
}
else if(c>=97&&c<=122){
        c=(char) (c-32);
        System.out.print("Converted to Uppercase :"+c);
}
else
    System.out.println("invalid Character Entered  :" +c);

}


  public static void main(String[] args) {
    // TODO Auto-generated method stub
    CaseConvert obj=new CaseConvert();
    obj.input();
    obj.convert();
    }

}



/*OUTPUT..Enter Any Character :A Converted to Lowercase :a 
Enter Any Character :a Converted to Uppercase :A
Enter Any Character :+invalid Character Entered  :+*/