In Project#3 you read in lines from a file and tested each to see if it was a pa
ID: 3904078 • Letter: I
Question
In Project#3 you read in lines from a file and tested each to see if it was a palindrome or not. In this Lab you will take your working solution from that assignment and transplant your code into a boolean method named isPalindrome(). As usual you are given a starter file with the main written. This time you will add your code inside the isPalindrome methods that is just an empty shell.
The expected output for Lab#4 is IDENTICAL to what Project#3 produced. The only difference is that your main program will call your boolean method isPalindrome() to determine whether the line is to be printed or not.
// Lab4.java Starter File Uses a method to print only palindromes from a text file
import java.io.*; // BufferedReader
import java.util.*; // Scanner
public class Lab4
{
public static void main (String args[]) throws Exception // i.e. the input file you put on cmd line is not in directory
{
// ALWAYS TEST FIRST TO VERIFY USER PUT REQUIRED INPUT FILE NAME ON THE COMMAND LINE
if (args.length < 1 )
{
System.out.println(" usage: C:\> java Lab4 <input filename> "); // i.e. C:> java Lab4 L4input.txt
System.exit(0);
}
Scanner infile = new Scanner( new File(args[0]) ); // we read our text file line by line
while( infile.hasNextLine() )
{
String line = infile.nextLine();
if ( isPalindrome(line) )
System.out.println(line);
}
infile.close();
} // END MAIN
// RETURNs true if and only if the string passed in is a palindrome
static boolean isPalindrome( String line )
{
CODE GOES HERE
return false; // Just to make it compile. You change as needed
}
} // END LAB4 CLASS
Command Prompt C: Users imDesktoplab-04 solution>java Lab4 L4input.txt Madam I mAdam Stanley Yelnats wow radar wow palindromic cimordnilap C: Users imDesktoplab-04solution»-Explanation / Answer
Please do rate this answer positive, If i was able to help you. Let me know if you have any issues in comments
public class Lab4
{
public static void main(String args[]) throws Exception // i.e. the input
// file you put on
// cmd line is not
// in directory
{
// ALWAYS TEST FIRST TO VERIFY USER PUT REQUIRED INPUT FILE NAME ON THE
// COMMAND LINE
if (args.length < 1)
{
System.out.println(" usage: C:\> java Lab4 <input filename> "); // i.e.
// C:>
// java
// Lab4
// L4input.txt
System.exit(0);
}
Scanner infile = new Scanner(new File(args[0])); // we read our text
// file line by line
while (infile.hasNextLine())
{
String line = infile.nextLine();
if (isPalindrome(line))
System.out.println(line);
}
infile.close();
} // END MAIN
// RETURNs true if and only if the string passed in is a palindrome
static boolean isPalindrome(String line)
{
// Please write your code after this line
String revStr = "";
for (int i = 0; i < line.length(); i++) {
revStr = line.charAt(i) + revStr;
}
// for easier comparison
line = line.toLowerCase();
revStr = revStr.toLowerCase();
if (line.compareTo(revStr) == 0) {
return true;
}
return false;
}
} // END LAB4 CLASS
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.