Split Contact Name Into First, Middle and Last name components.

SplitContactName.cls

String s = 'FirstName MiddleName LastName AnotherName';
String[] arrayS = s.split(' ', 3);
System.debug ( 'First :- '+ getFirstName(arrayS) );
System.debug ('Middle :-'+ getMiddleName(arrayS) );   
System.debug ('Last Name :-'+ getLastName(arrayS) );


s = 'FirstName MiddleName LastName';
arrayS = s.split(' ', 3);
System.debug ( 'First :- '+ getFirstName(arrayS) );
System.debug ('Middle :-'+ getMiddleName(arrayS) );   
System.debug ('Last  :-'+ getLastName(arrayS) );


s = 'FirstName LastNameAnotherName';
arrayS = s.split(' ', 3);
System.debug ( 'First :- '+ getFirstName(arrayS) );
System.debug ('Middle :-'+ getMiddleName(arrayS) );   
System.debug ('Last Name :-'+ getLastName(arrayS) );   

s = 'Lastname';
arrayS = s.split(' ', 3);
System.debug ( 'First :- '+ getFirstName(arrayS) );
System.debug ('Middle :-'+ getMiddleName(arrayS) );   
System.debug ('Last Name :-'+ getLastName(arrayS) );


String getFirstName(String[] arraySP){
    if(arraySP != null && arraySP.size() >= 2 ){
        return arrayS[0];
    }
    return '';
}

String getLastName(String[] arraySP){
    return arraySP == null || arraySP.isEmpty() ? '' : arraySP[arraySP.size() - 1];
}

String getMiddleName(String[] arraySP){
    if( arraySP != null && arraySP.size() >= 3 ){
        return arraySP[1];
    }
    
    return '';
}