JAVA program to calculate age, using GUI.

This program calculates the age. Input is taken from the user through a Graphical User Interface (GUI). We will be using the following components in our program.

    Frame
    TextField
    Label
    Button

Step 1: Creating a Frame
First thing we do is, create a frame. A frame is nothing but the actual window that you’ll see when the program is executed.
Frame is initialized at line 23:

After initializing our frame, we set is size and location on the screen. This is done at line 26:

By default, the frame’s visibility is set to false, i.e the frame is not visible. So we have to set its visibility to true. Done at line 24:

Next thing we do is set LayOut for the frame, we have put a FlowLayout in this program.


Step 2: Initialize other components.

After finishing the frame, we initialize Buttons, TextField and Label. This is done from line 13 till 22.

Step 3: Add Components to the frame.
After initializing frame and other components, we add those components to the frame. Syntax for doing this is:

Step 4: Add ActionListeners to the frame.

This is the most important part of the program. ActionListeners tell the program that an event has occurred, for example a button is clicked.
We add ActionListener to all the three buttons, so that our program reacts accordingly when a button is clicked.

After adding ActionListener, we create classes which will handle the events. In this program, we have created Class Clear and Exit to perform the required task.

Step 5: Calculate age and display the result.

Whenever the Submit button is clicked, actionPerformed class stores the user entered data in the equivalent variables.
Note: We have put the code in a try block so that we can catch the exception if user doesn’t input a valid date. (If user enters a String or Invalid month.)

After collecting data from the TextFields, our next task will be to parse them into int so we can do the necessary calculations.
CalculateAge() :
The objective of this function is to calculate age based on users input. We first find out current date,month and year from the system using in-built class Date found in

That was just a brief summary of the program. If you have any questions, feel free to ask.

Program:

Output:
Ouput for age calculator

Tested in Eclipse and Command Line.

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  • Manoj

    it is showing an age less than 1 year.

    • Vlad

      What input did you provide Manoj?