Working with Strings

The Aims

This lab will introduce you to using the Java string classes.

Manipulating Text

1. Create a new Java class called "TestStrings" with a main method. Each of the following questions can be completed in the main method.

2. Create a String called filename with the value "example.doc", change the value to "example.bak".

3. Input two Strings and test them see if they are equal. If they are not equal show which of them lexicographically further forward (in the dictionary!).

4. Find the number of times "ow" occurs in "the quick brown fox swallowed down the lazy chicken"

5. Check to see whether a given string is a palindrome (eg "Live not on evil")

Click here to see the sample solution

class TestStrings {

   public static void main(String[] args) {

	  String filename = "example.doc";
	  filename = "example.bak";

	  String one = "Hello";
          String two = "Goodbye";
   
          if (one.equals(two)) {
              System.out.println("The two strings are equal.");
	  }
	  else if (one.compareTo(two) < 0) {
		System.out.println(one + " comes before " + two);
	  }
	  else {
		System.out.println(two + " comes before " + one);
	  }

	  String phrase = "the quick brown fox swallowed down the lazy chicken";
	 
	  // Count occurrences of "ow" 
	  int countOfOw = 0;
	  int index = phrase.indexOf("ow");	
	  while (index != -1) {
	      countOfOw++;
	      index = phrase.indexOf("ow", index + 1);
	  }
	 
	  System.out.println ("ow occurs " + countOfOw + " times in "+ phrase); 


	  String text = "Live not on evil";
	  text = text.replaceAll(" ", "").toLowerCase();
	  String reversed = new StringBuilder(text).reverse().toString();
	  if (text.equals(reversed)) {
	      System.out.println(text + " is a palindrome.");
	  } else {
	      System.out.println(text + " is not a palindrome.");
	  }
	  
	}
   }