Camel Case in Java

Java names its classes, interfaces, methods, as well as variables using camel-case syntax. If the name consists of two words, the second word will always begin with a capital letter, such as maxMarks(), lastName, or ClassTest, and all whitespace will be removed.

Camel case can be used in two different ways:

1. Use lowercase camel case, when the first letter of the initial word is lowercase. When naming the methods as well as variables, this convention is typically followed. For examples, FirstName, LastName, ActionEvent, printArray(), etc.
2. The title case, also known as upper camel case, is used when the first letter of the beginning word is capitalized. This naming style is typically used for classes and interfaces. For examples, Employee, printable, etc.

Changing a Standard String to a Camel Case

Simply deleting the spaces from a string will transform it to either the lowercase or uppercase camel case style.

Example of a Lower Camel Case

Input: Learn the programming languages

Output: learnTheProgrammingLanguages

Example of an Upper Camel Case

Input: learn java language

Output: LearnJavaLanguage

Steps

Step 1: The character array is traversed character by character until the end using the following algorithm.

Step 2: When lower camel case comes next, the initial letter of a string at index = 0 is changed to lower case, otherwise, it is converted to upper case 

Step 3: When there are any spaces in the array, the letter that follows the space gets capitalized.

Step 4: If the non-space characters appear, it is copied to the array that results.

Time complexity

Time complexity: O(n)

Since all operations need one traversing of the string, the total time needed by the approach is linear.

Auxiliary Space:

Auxiliary Space: O(1)

Since no additional array is utilized, the algorithm's space requirements are constant.

Programs on Camel Case in Java

Lower Camel Case Conversion of String

public class LowerCamel
{ 
    static String convertString( String s )  
    { 
        int ctr = 0 ;
        int n = s.length( ) ;  
        char ch[ ] = s.toCharArray( ) ;  
        int c = 0 ;
        for ( inti = 0; i< n; i++ )  
        {  
if( i == 0 ) 
ch[i ] = Character.toLowerCase( ch[ i ] ) ;  
            if ( ch[ i ] == ' ' )  
            { 
ctr++ ;
ch[i + 1 ] = Character.toUpperCase( ch[ i + 1 ] ) ; 
continue ;
            }  
            else  
ch[c++ ] = ch[ i ] ;  
        } 
        return String.valueOf( ch, 0, n - ctr ) ;  
    }  
    public static void main( Stringargs[ ] )  
    {  
        String str = "Hello People" ;
System.out.println( convertString( str ) ) ; 
        String str1 = "Learn" ;
System.out.println( convertString( str1 ) ) ; 
        String str2 = " The best content from the javatpointtutourial" ;
System.out.println( convertString( str2 ) ) ;  
    }  
}  

Output

helloPeople
learn
TheBestContentFromTheJavatpointTutourial

Upper Camel Case Conversion for String

public class UpperCamel
{  
    static String convertString( String s )  
    { 
        int ctr = 0 ;
        int n = s.length( ) ; 
        char ch[ ] = s.toCharArray( ) ;  
        int c = 0 ;
        for ( inti = 0; i< n; i++ )  
        { 
if( i == 0 )  
ch[i ] = Character.toUpperCase( ch[ i ] ) ;  
            if ( ch[ i ] == ' ' )  
            {  
ctr++ ;
ch[i + 1 ] = Character.toUpperCase( ch[ i + 1] ) ;  
continue ;
            } 
            else  
ch[c++ ] = ch[ i ] ;  
        }  
        return String.valueOf( ch, 0, n - ctr ) ;  
    }  
    public static void main( Stringargs[ ] )  
    {  
        String str = "programming language" ;
System.out.println( convertString( str ) ) ;  
        String str1 = "java t point" ;
System.out.println( convertString( str1 ) ) ;   
        String str2 = "i love java language" ;
System.out.println(convertString( str2 ) ) ;  
    }  
}   

Output

ProgrammingLanguage
JavaTPoint
ILoveJavaLanguage

Example

public class UpperCamel
{  
    static String convertString( String s )  
    { 
        int ctr = 0 ;
        int n = s.length( ) ; 
        char ch[ ] = s.toCharArray( ) ;  
        int c = 0 ;
        for ( inti = 0; i< n; i++ )  
        { 
if( i == 0 )  
ch[i ] = Character.toUpperCase( ch[ i ] ) ;  
            if ( ch[ i ] == ' ' )  
            {  
ctr++ ;
ch[i + 1 ] = Character.toUpperCase( ch[ i + 1] ) ;  
continue ;
            } 
            else  
ch[c++ ] = ch[ i ] ;  
        }  
        return String.valueOf( ch, 0, n - ctr ) ;  
    }  
    public static void main( Stringargs[ ] )  
    {  
        String str = " programming language" ;
System.out.println( convertString( str ) ) ;  


    }  
}

Output

ProgrammingLanguage