error: incompatible types: String cannot be converted to char opp = JOptionPane.showInputDialog("Enter Method");

Question

I am adding this a code this give below error:

// Printing in a dialog box import javax.swing.JOptionPane;

public class ExampleWorking {
    public static void main(String[] args) {
        String  firstNumber,
                secondNumber,
                opp;
        int number1,
            number2,
            results;
        boolean use;
        firstNumber = JOptionPane.showInputDialog("Enter First integer");
        secondNumber = JOptionPane.showInputDialog("Enter Second integer");
        opp = JOptionPane.showInputDialog("Enter Method");
        number1 = Integer.parseInt(firstNumber);
        number2 = Integer.parseInt(secondNumber);
        use = boolean.parseBoolean(opp);
        if (use="+") {
            results= number1 + number2;
        }
        else{
            if(use="-"){
                results=number1 - number2;
            }
            else{
                if (use="*"){
                    results=number1 * number2;
                } else {
                    if (use="/") {
                        results=number1/number2;
                    } else {
                        System.out.println("Hello World");
                    }
                }
            }
        }
        JOptionPane.showMessageDialog(null, "The Results is " + results , "Results", JOptionPane.PLAIN_MESSAGE);
        System.exit(0);
    }
}

Error

ExampleWorking1.java:21: error: incompatible types: String cannot be converted to char

opp = JOptionPane.showInputDialog("Enter Method");

1 error

score 0 · Answer 1 · answered Mar 31 '18 at 10:12

Problem with your code is that you have multiple compilation errors, and although none of them corresponds to the error message you've added, fixing them will solve your problem.

Your variable use is of type boolean, but you're trying to assign a String to it, which are incompatible types, and also is not needed in your case. You don't need a boolean variable for storing a sign.
In all of your if statements, you're using operator = , which is used for assigning value to variable and not for comparison (for more information about assigning values, see this tutorial). If you want to compare values, you should use == for primitive data types, and equals method for String - you can see why here.

Once you fix incorrect type of use variable and use proper comparison for your data type instead of re-assigning variable value inside of if condition, your code will be working fine.

error: incompatible types: String cannot be converted to char opp = JOptionPane.showInputDialog("Enter Method");

1 Answers1