将 JLabel 文本设置为数字循环

Question

I am writing a simple Java application where the user provides two inputs; a starting number and an ending number. Once a button is clicked, the application should display all numbers between the starting number and the ending number on the screen.

Ex. (1 2 3 4 5) if starting = 1 and ending = 5

Here is the loop I am using to output the numbers

Int starting = 1;
Int ending = 5;

for(starting; starting <= ending; starting++){
    //"Output" is a JLabel object
    Output.setText(starting);
}

I would expect this to set the content of Output to 1 2 3 4 5 . Though by the end of the loop, the content of Output is just the last number in the sequence (5 in this case).

Could someone please explain why I am seeing this behavior?

Answer 1

You are overriding the text in the JLabel in every iteration. That's why the JLabel always shows the last number.

Concatenate all the integers in a single string, then after the loop completes, set the text of the JLabel to be the concatenated string.

 String result = "";
    for (int starting = Integer.parseInt(Start.getText()); starting <= ending; starting++){
        result += starting;
    }
    output.setText(result);

Btw: you have syntax errors.