CSci 2101 Data Structures: Lab 6

Problem 1: working with strings

Important: Make sure that your program doesn't require any changes if the number of elements in the array changes.

Question 1 Write a loop to count the number of case-sensitive and non-case-sensitive matches for a given string in the array. Print out the counters after the loop. Test your code on the given array and the strings find1 and find2 (see the program below).

Question 2 Write a loop to find the longest string in the array. Print out the longest string after the loop. If several strings have the same length, any one of them will do.

Question 3 Define a new string glueAll. Write a loop which goes through the array and concatenates all the strings of the array, separated by spaces, into the string glueAll. After the loop replace the last white space in glueAll by !.
For example, if the array is {"Roses","are","red"}, the string glueAll will have
Roses are red!
in it.

public class StringArray {
	
	public static void main(String[] args) {
	    String [] strings = {"I","do","not","like","green","eggs","and",
				 "ham","I","DO","Not","like","it","Sam","I",
				 "am"};
	    String find1 = "I";
	    String find2 = "not";

	    // Quest. 1: find all case-sensitive and non-case-sensitive 
	    // matches for each of the given strings

	    // Quest. 2: find the longest string in the array, print it

	    // Quest. 3: concatenate all the strings into one string

	}
 
}

Problem 2: strings and characters

• Create a string with some characters in it (they may be letters, digits, punctuation marks, etc.)
• Write a loop that goes through the string character-by-character using a charAt() method of a String (see String API). In the loop count the number of letters in the string. To check if a character is a letter, use the method isLetter() of the class Character. More precisely,

  
      char c = 'A';
      boolean b1 = Character.isLetter(c);
      c = '6';
      boolean b2 = Character.isLetter(c);
  

  makes b1 true because 'A' is a letter and makes b2 false because '6' is not a letter.
• Print the value of the letter counter after the loop.
• Test your program on several different strings, comment out your test cases and write the results.

Problem 3: memory picture

public class StringsAndBuffers {
    public static void main(String [] args) {
	String s1 = "something";
	String s2 = s1.toUpperCase();
	System.out.println("s1.equals(s2) = " + s1.equals(s2));

	String s3 = s2.toLowerCase();
	s2 = s3; 
	System.out.println("s1 == s2 is " + (s1 == s2));
	System.out.println("s2 == s3 is " + (s2 == s3));

	StringBuffer sb1 = new StringBuffer("something else");
	StringBuffer sb2 = new StringBuffer("something different");
	StringBuffer sb3 = sb2;
	sb3.insert(10,"entirely ");
	System.out.println(sb2);
	sb2 = sb1.replace(0,4,"any");
	System.out.println(sb1);
	System.out.println(sb2);
	System.out.println("sb1 == sb2 is " + (sb1 == sb2));
                
    }
}

Problem 4: Palindromes

Important: do not change the given array. Print it out at the end to make sure that no elements have changed.

public class Palindromes {
    public static void main(String [] args) {
	StringBuffer [] words = new StringBuffer[7];
	words[0] = new StringBuffer("Rob");
	words[1] = new StringBuffer("sees");
	words[2] = new StringBuffer("Bob");
	words[3] = new StringBuffer("and");
	words[4] = new StringBuffer("Bob's");
	words[5] = new StringBuffer("sister");
	words[6] = new StringBuffer("Anna");
	
	// write a loop to print out all the palindromes

    }
}

Problem 5 (extra credit)