Question

Write a class called VLPUtility with the following static methods: Java Language

1. concatStrings that will accept a variable length parameter list of Strings and concatenate them into one string with a space in between and return it.

2. Overload this method with two parameters, one is a boolean named upper and one is a variable length parameter list of Strings. If upper is true, return a combined string with spaces in upper case; otherwise, return the combined string as is.

3. makeWord: accepts a variable length parameter list of char values and make a word from these character values, return the result as a String.

4. Overload this method so that it accepts a variable length parameter list of char values, a boolean variable named reverse, and an int variable named repeat.

a. If the boolean variable is true, the combined char values will be reversed.

b. Based on the value of the int variable, the combined char values will be repeated.

c. The result will be returned. For example, if ‘a’, ‘l’, ‘l’, ‘o’, ‘w’ are passed, it will be combined into “allow”. If the boolean variable is true, it will be reversed to “wolla”; if the int variable value is 2, it will be either “allowallow” or “wollawolla”

Answer 1

The given java methods will be defined as follows:

• Create a class VLPUtility.
• Define method concatStrings. This method will take variable number arguments of type String. In the method body, initialize an empty string variable. Use for each loop to traverse the variable length array of arguments and append each string and a space to the string variable. Then return the string.
• Define overloaded method concatStrings. This method will take a boolean variable also as a parameter. If the variable is true, change the strings to upper and add this and a space to the string variable and return it. Otherwise, only concatenate the strings and return the result.
• Define the makeWord method. This method will take variable length arguments of type char. Define the string variable as empty. Use loop to traverse the array of arguments and append the characters to the string. Return the result.
• Define the overloaded method makeWord. It will take a boolean variable and an int variable also as parameters. The int variable will define the number of times the string will be repeated. The boolean variable defines whether the string has to be reversed or not.

The java program:

//class VLPUtility
class VLPUtility{
    
    //method to concate strings
    public String concatStrings(String ... str){
        String result="";
        
        //add each string in the array
        for(String i:str){
            result += i + " ";
        }
        
        //return the result
        return result;
    }
    
    //overloaded method concatStrings
    public String concatStrings(boolean upper, String ... str){
        String result = "";
        
        //upper is true
        if (upper){
            for(String i:str){
                //change string to upper case and add
                result += i.toUpperCase() + " ";
            }
        }
        
        //otherwise just add the strings 
        else{
            for(String i:str){
                result += i;
            }
        }
        
        //return the result
        return result;
    }
    
    //method to make a word using given characters
    public String makeWord(char ... letters){
        String result = "";
        
        //add char to empty string
        for(char ch:letters){
            result += ch;
        }
        
        //return the result
        return result;
    }
    
    //overloaded method makeWord
    public String makeWord(boolean reverse, int repeat, char ... letters){
        int s = letters.length;    //find the length of arguments
        
        String result = "";
        
        //if reverse is true
        //append words in reverse
        if (reverse){
        for(int i=1;i<=s;i++){
            result += letters[s-i];
        }
        }
        
        //otherwise add as it is
        else {
            for(char ch:letters){
            result += ch;
        }
        }
        
        //for repeating words
        String result2 = "";
        
        for(int i=0;i<repeat;i++)
        result2 += result;
        
        result = result2;
        
        //return the result
        return result;
    }
    
}

class Main{
        
    public static void main(String[] args) {
        
        //create object of VLPUtility class
        VLPUtility V= new VLPUtility();
        
        //call method concatStrings
                System.out.println(V.concatStrings("abc","def","geh"));
                
                //cal overloaded method concatStrings
                System.out.println(V.concatStrings(true,"abc","def","geh"));
                
                //call overloaded method concatStrings
                System.out.println(V.concatStrings(false,"abc","def","geh"));
                
                //call method makeWord
                System.out.println(V.makeWord('c','a','t'));
                
                //call overloaded method makeWord
                System.out.println(V.makeWord(true,3,'c','a','t'));
        }
}

Sample output: