In this tutorials will teach how to make a calculator in java step by step. How to create the calculator in java swing application in best coding practice.
First Step
Declare the variables
1 2 3 4 5 | String CalTotal; int num1; int num2; String option; int result; |
You have to paste the below Codes 1 to 0 buttons
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 | private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "1"); } private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) { CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "2"); } private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) { CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "3"); } private void jButton4ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "4"); } private void jButton5ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "5"); } private void jButton6ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "6"); } private void jButton7ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "7"); } private void jButton8ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "8"); } private void jButton9ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "9"); } private void jButton10ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: CalTotal = txtTotal.getText(); txtTotal.setText(CalTotal + "0"); } |
Paste the following codes to +,-,*,/ button
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 | private void jButton11ActionPerformed(java.awt.event.ActionEvent evt) { option = "+"; num1 = Integer.parseInt(txtTotal.getText()); txtTotal.setText(""); } private void jButton12ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: option = "-"; num1 = Integer.parseInt(txtTotal.getText()); txtTotal.setText(""); } private void jButton13ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: option = "*"; num1 = Integer.parseInt(txtTotal.getText()); txtTotal.setText(""); } private void jButton14ActionPerformed(java.awt.event.ActionEvent evt) { // TODO add your handling code here: option = "/"; num1 = Integer.parseInt(txtTotal.getText()); txtTotal.setText(""); } |
Paste the following codes inside the = Button
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | private void jButton15ActionPerformed(java.awt.event.ActionEvent evt) { num2 = Integer.parseInt(txtTotal.getText()); if(option.equals("+")) result = num1 + num2; if(option.equals("-")) result = num1 - num2; if(option.equals("*")) result = num1 * num2; if(option.equals("/")) result = num1 / num2; txtTotal.setText(result + ""); } |
Paste the following codes inside the Clear Button
1 2 3 4 5 6 7 8 | private void jButton16ActionPerformed(java.awt.event.ActionEvent evt) { txtTotal.setText(""); result = (0); num1 = (0); num2 = (0); } |
i have attached the video link below. which will do this tutorials step by step
