Thread: java programming assignment help

how will i test the length

Look at the API doc for the String class. It has a method that will give you the length.

how will it confirm that the input is not a character?

Define what you mean by a character? The only data that can be entered easily via the keyboard is a character. Look at the Character class's methods if you want to know what kind of character was read into the program.

The API doc: Java Platform SE 7

It's at this link:
The API doc: Java Platform SE 7

how to fix this??
when i input 81
my program output the squareroot is 2.828 something...

/**
* @(#)activity2.java
*
*
* @author
* @version 1.00 2012/10/1
*/
 
import javax.swing.*;
public class aa
{
public static void main(String[]args)
{
String input="";
char inputs;
double x;
int loop=0;
do{
input=JOptionPane.showInputDialog(null,"Enter A Character: ");
inputs=input.charAt(0);
if(Character.getType(inputs) == Character.CURRENCY_SYMBOL)
{
JOptionPane.showMessageDialog(null,"The character is a symbol.");
}
else if(Character.isDigit(inputs))
{
int num= inputs -'0';
JOptionPane.showMessageDialog(null,"The character is a Digit.");
JOptionPane.showMessageDialog(null,"The square root of "+inputs+" is "+Math.sqrt(num));
}
else if (input.length()>1)
{
JOptionPane.showMessageDialog(null,"Invalid Input. Input a character only.");
}
else if(Character.isLetter(inputs))
{
if(Character.isLowerCase(inputs))
{
JOptionPane.showMessageDialog(null,"Lowercase");
}
if(Character.isUpperCase(inputs))
{
JOptionPane.showMessageDialog(null,"UpperCase");
}
}
else
{
JOptionPane.showMessageDialog(null,"The character is a symbol.");
}
loop = JOptionPane.showConfirmDialog(null,"Try Again?[Y/N]","repeat",JOptionPane.YES_NO_OPTION);
if(loop == JOptionPane.NO_OPTION)
{
JOptionPane.showMessageDialog(null,"Thank You For Using The Program.");
}
}while(loop == JOptionPane.YES_OPTION);
}
}

Please edit you post and change the quote tags to code tags.
Also please format the code. All statements should NOT start in the first column.

What is the square root of 8?

Your code only works with one character

The code reads the full input from the user into a variable and then takes the first character.
If you want all of the input, use it instead of just using the first character.


Please edit your code and format it. All statements should not start in the first column.
See: Code Conventions for the Java Programming Language: 4. Indentation

If you want the program to give an error message for input of more than one character, have it test the length of the String it reads in from the user.


Please edit your code and format it. All statements should not start in the first column.
See: Code Conventions for the Java Programming Language: 4. Indentation

There are more than one if statement. Which one do you want done first?
With if/else if statements, the first one that is true is the only one that will be executed. The following ones will be skipped.

Your code is hard to read and understand.
Please edit your code and format it. All statements should not start in the first column.
See: Code Conventions for the Java Programming Language: 4. Indentation

already edited the if but still i have the error

/**
* @(#)activity2.java
*
*
* @author
* @version 1.00 2012/10/1
*/
 
import javax.swing.*;
public class activity2
{
public static void main(String[]args)
{
String input="";
char inputs;
double x;
int loop=0;
do{
input=JOptionPane.showInputDialog(null,"Enter A Character: ");
inputs=input.charAt(0);
if(Character.getType(inputs) == Character.CURRENCY_SYMBOL)
{
JOptionPane.showMessageDialog(null,"The character is a symbol.");
}
else if(Character.isDigit(inputs))
{
JOptionPane.showMessageDialog(null,"The character is a Digit.");
JOptionPane.showMessageDialog(null,"The square root of "+input+" is "+Math.sqrt(Double.parseDouble(input)));
}
else if (input.length()>1)
{
JOptionPane.showMessageDialog(null,"Invalid Input. Input a character only.");
}
else if(Character.isLetter(inputs))
{
if(Character.isLowerCase(inputs))
{
JOptionPane.showMessageDialog(null,"Lowercase");
}
else if(Character.isUpperCase(inputs))
{
JOptionPane.showMessageDialog(null,"UpperCase");
}
}
else
{
JOptionPane.showMessageDialog(null,"The character is a symbol.");
}
loop = JOptionPane.showConfirmDialog(null,"Try Again?[Y/N]","repeat",JOptionPane.YES_NO_OPTION);
if(loop == JOptionPane.NO_OPTION)
{
JOptionPane.showMessageDialog(null,"Thank You For Using The Program.");
}
}while(loop == JOptionPane.YES_OPTION);
}
}

Your code is hard to read and understand.
Please edit your code and format it. All statements should not start in the first column.
See: Code Conventions for the Java Programming Language: 4. Indentation

Why won't you fix the posted code to make it easier to read and understand?
The statements should NOT all start in the first column. Add spaces to indent as per the link that has been posted several times.

Did you understand what I said in post#36?

Do you understand what I said in post #36?

There is more than one if statement. Which one do you want done first?
With if/else if statements, the first one that is true is the only one that will be executed. The following ones will be skipped.

Your formatting is still wrong. It should look like this:

	}
 
	loop = JOptionPane.showConfirmDialog(null,"Try Again?[Y/N]","repeat",JOptionPane.YES_NO_OPTION);
	if(loop == JOptionPane.NO_OPTION)
	{
		JOptionPane.showMessageDialog(null,"Thank You For Using The Program.");
	}
   }while(loop == JOptionPane.YES_OPTION);
 } 
}

I thought I did. If what I said in post #36 is not the problem, can you please explain what the problem is? Make a list the the steps you do and the steps the computer does and then explain what is wrong with the computer's responses. For example:
1) I enter: s
2) the computer says: lowercase
3) I enter: 4
4) the computer says: 2
5) I enter:this is another
6) The computer says: lowercase <<<<<< This should be: Invalid input

program should output invalid input because 10String is not a pure number it also has letter on it..

Would 1234 be a valid input?

One way to check if a String contains only numeric digits would be to use the Integer class's parseInt() method inside of a try{}catch block. The parseInt() method will throw an exception if the String it gets is not a valid/pure number.

Another way to check if a String contains only numeric digits would be to write a loop that gets the characters in the String one at a time and tests each character with the isDigit() method.

If you don't understand how to use the try{} catch block use the second way.

i am using joption not buffered

I don't understand what that is about.

Write a small program for testing.
Define a String with several characters that will be scanned in the loop.

Define a loop that gets the characters one at a time from the String.
The loop needs to go around one time for each character in the String.