CODEWITHSUNDEEP
javaarraysjtextfield
wolverine961
wolverine961

Reputation: 15

Store JTextField text into array and sum - Java

I want to somehow store the text from JTextField into array and then sum it.

btn.addActionListener(new ActionListener() {
  public void actionPerformed(ActionEvent e) {
    //fldi is the JTextField I want to get text from
    int ii = Integer.parseInt(fldi.getText());
  }
});

What should I do next? how can I split text from there, for example if user input is "256" I think it should be stored in array like "2", "5", "6".

EDIT: So after Jake Miller's help I've got:

String input = fldi.getText();
            int sum = 0; 

            int[] values = new int[input.length()];
            for(int i = 0; i < input.length(); i++) {
            int number;
            if(input.substring(i, i+1).equals("-")) {
                number = Integer.parseInt(input.substring(i, i+2));
            } else {
                number = Integer.parseInt(input.substring(i, i+1));
            }
            values[i] = number;         
                sum = sum + values[i];
            }

            fldwo.setText(Integer.toString(sum));

But when I try it for negative numbers like "-2" and "-1" values array stores 4 values "-2", "2", "-1", "1" and the sum at the end is 0, but it should be -3.

Upvotes: 0

Views: 1003

Answers (1)

Jake Miller
Jake Miller

Reputation: 2642

Don't parse it right away. Store the input into a String, use a loop to use .substring() to go through each character in the String, and parse each individual number and store into an int array.

String input = fldi.getText();
int[] values = new int[input.length()];
for(int i = 0; i < input.length(); i++) {
    values[i] = Integer.parseInt(input.substring(i, i+1));
}

If they input 256, then the array will have 3 values: 2, 5, and 6

EDIT

For negative numbers, you'll need to have a check for the character "-" as it indicates a negative number. Then, you'll use substring(i, i+2) to take two characters as opposed to one (the - and the number itself). You also don't need the array. You can simply add each number you parse to the sum directly. You also should use a while loop and increment i on your own. If you find a negative number, you're using 2 characters, which means you need to increment i by two instead of 1.:

    int sum = 0;
    int i   = 0;
    while(i < input.length()) {
        int number;
        if(input.substring(i, i+1).equals("-")) {
            number = Integer.parseInt(input.substring(i, i+2));
            i += 2;
        } else {
            number = Integer.parseInt(input.substring(i, i+1));
            i++;
        }
        sum += number;
    }

An example:

A user inputs 125-35. The first three characters will NOT be equal to "-", therefore they'll simply be parsed and stored into the values array. Once you reach the 4th character (3rd index), the character will be a "-", so the if statement will cause number to be equal to -3 as the substring now returns two characters as opposed to one.

Upvotes: 1

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