Question

Restrictions: You are not allowed to use anything from the String, StringBuilder, or Wrapper classes. In general, you may not use anything from any other Java classes, unless otherwise specified. You are not allowed to use String literals in your code ("this is a string literal"). You are not allowed to use String objects in your code. The methods must be implemented by manipulating the data field array, The CSString Class: NOTE: Pay very careful attention to the method header as well as what the method should return. As always use the correct access modifiers, Once a CSString object has been created, you should never change the characters in that string. Any changes should result in a new CSString object being returned. Data Fields: char[] text: This class shall have a data field that is an array of characters. NOTE: No other data fields are allowed. Constructors: CSString(charl] text): This constructor shall take an array of characters as input. This constructor shall use the System. arraycopy() method to copy the data from the parameter array to the data field array, which shall make a deep copy of the data. This class shall have no other constructors. Methods: charAt(int index): This method shall take an integer index as input. The index value cannot be negative. The index value cannot be larger than the length of the string – 1. If the index is not valid, display an error message and return '\00000': This method shall return the character at the given index. concat(CSString other): This method shall take a CSString object as input. This method shall return a new CSString object created by concatenating the source string and the parameter string together. endsWith(CSString suffix): This method shall take a CSString object as input. This method shall return true if the source string ends with the exact character sequence given in the suffix string, return false otherwise, equals(CSString other): This method shall take a CSString object as input. This method shall return true if the source string is exactly equal to the other string, This method does not ignore the case of a character when checking for equality. i.e. 'A' == 'a' should be considered a result of false. TWO CSString objects are equal if all of the following are true! They both have the same number of characters. They both have the exact same characters in the exact same order from beginning to end. equalsIgnoreCase (CSString other): This method shall take a csString object as input. This method shall return true if the source string is exactly equal to the other string. This method ignores the case of a character when checking for equality. 1.e. 'A' == 'a', 'A' == 'A', 'a' == 'a', should all be considered a result of true. HINT: You are allowed to use the Character.toLowerCase() method from the Character class to help implement this method. TWO CSString objects are equal if all of the following are true: They both have the same number of characters. They both have the exact same characters in the exact same order from beginning to end. Length(): This method shall take no parameters as input. This method shall return the length of the csString (number of characters) as an integer. startsWith(CSString prefix):

language is java

Answer 1

Program:

//class CSString
class CSString
{
   //data fields
   char[] text;
  
   //constructor
   public CSString(char[] text)
   {
       this.text = new char[text.length];
       System.arraycopy(text, 0, this.text, 0, text.length);
   }
  
   //method to return a character at index
   public char charAt(int index)
   {
       if(index<0 || index>text.length-1)
       {
           System.out.println ("Invalid index");
           return '\u0000';
}
       return text[index];
   }
  
   //method to concat two CSString objects
   public CSString concat(CSString other)
   {
       char s[] = new char[text.length + other.length()];
       int i;
       for(i=0; i<text.length; i++)
       {
           s[i] = text[i];
       }
       for(int j=0; j<other.text.length; j++, i++)
       {
           s[i] = other.text[j];
       }
       CSString string = new CSString(s);
       return string;
   }
  
   //method checks the CSString object ended with the suffix
   public boolean endsWith(CSString suffix)
   {
       int n = text.length - suffix.text.length;
       for(int i=0; i<suffix.text.length; i++)
       {
           if(text[n+i]!=suffix.text[i])
               return false;
       }
       return true;
   }
  
   //method checks two CSString objects are equal or not
   //if equal return true otherwise false
   public boolean equals(CSString other)
   {
       for(int i=0; i<text.length; i++)
       {
           if(text[i]!=other.text[i])
               return false;
       }
       return true;
   }
  
   //method checks two CSString objects are equal or not ignoring case
   //if equal return true otherwise false
   public boolean equalsIgnoreCase(CSString other)
   {
       for(int i=0; i<text.length; i++)
       {
           char c1 = Character.toLowerCase(text[i]);
           char c2 = Character.toLowerCase(other.text[i]);
          
           if(c1!=c2)
               return false;
       }
       return true;
   }
  
   //method to return the length of the CSString
   public int length()
   {
       return text.length;
   }
  
   //method to create a substring of CSString object from begin
   public CSString substring(int begin)
   {
       if(begin<0 || begin>text.length-1)
       {
           System.out.println ("Invalid index");
           return null;
       }
          
       char s[] = new char[text.length - begin];
       for(int i=0; i<text.length - begin; i++)
       {
           s[i] = text[begin+i];
       }
      
       CSString string = new CSString(s);
       return string;
   }
  
   //method to create a substring of CSString object from begin to end-1
   public CSString substring(int begin, int end)
   {
       if(begin<0 || begin>text.length-1 || end<0 || end>text.length-1)
       {
           System.out.println ("Invalid index");
           return null;
       }
          
       char s[] = new char[end - begin];
       for(int i=0; i<end-begin; i++)
       {
           s[i] = text[begin+i];
       }
      
       CSString string = new CSString(s);
       return string;
   }
  
   //method to create a new CSString object with swapping cases
   public CSString swapCase()
   {
       CSString string = new CSString(text);
      
       for(int i=0; i<text.length; i++)
       {
           if(Character.isLowerCase(text[i]))
               string.text[i] = Character.toUpperCase(text[i]);
           else
               string.text[i] = Character.toLowerCase(text[i]);
       }
      
       return string;
   }
  
   //method to create a new CSString object with title cases
   public CSString titleCase()
   {
       CSString string = new CSString(text);
      
       string.text[0] = Character.toUpperCase(text[0]);
       for(int i=1; i<text.length; i++)
       {
           if(text[i-1]==' ' && text[i]!=' ')
               string.text[i] = Character.toUpperCase(text[i]);
       }
       return string;
   }
  
   //method to create a new CSString object with lower cases
   public CSString toLowerCase()
   {
       CSString string = new CSString(text);
      
       for(int i=0; i<text.length; i++)
       {
           string.text[i] = Character.toLowerCase(text[i]);
       }
      
       return string;
   }
  
   //method to create a new CSString object with upper cases
   public CSString toUpperCase()
   {
       CSString string = new CSString(text);

       for(int i=0; i<text.length; i++)
       {
           string.text[i] = Character.toUpperCase(text[i]);
       }
       return string;
   }
  
   //method to convert CSString object to String object and return
   public String toString()
   {
       String string = "";
      
       for(int i=0; i<text.length; i++)
       {
           string = string + text[i];
       }
       return string;
   }
}

//Demo class to testing
class Demo
{
   //main method
   public static void main (String[] args)
   {
       char s[] = {'a','b','c','d','e', 'f','g'};
       char s2[] = {'p','q','r','s','t'};
      
       //create two objects of CSString class
       CSString string = new CSString(s);
       CSString string2 = new CSString(s2);
      
       /******* Testing *******/
       System.out.println ("Length = " + string.length());
      
       System.out.println ("Char at 3: " + string.charAt(3));
      
       System.out.println ("The string is: "+ string);
      
       System.out.println ("Touppercase: " + string.toUpperCase());
      
       System.out.println ("Touppercase: " + string.toLowerCase());
      
       System.out.println ("Titlecase: " + string.titleCase());
      
       System.out.println ("Substring from 3: " + string.substring(3));
      
       System.out.println ("Substring from 3 to 6: " + string.substring(3, 6));
      
       System.out.println ("Concat of two string: " + string.concat(string2));
      
       System.out.println ("Is equal? " + string.equals(string2));
      
       System.out.println ("Is equal? " + string.equalsIgnoreCase(string2));
      
       System.out.println ("EndsWith? " + string.endsWith(string2));
   }
}

Output:

Length = 7
Char at 3: d
The string is: abcdefg
Touppercase: ABCDEFG
Touppercase: abcdefg
Titlecase: Abcdefg
Substring from 3: defg
Substring from 3 to 6: def
Concat of two string: abcdefgpqrst
Is equal? false
Is equal? false
EndsWith? false

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