How to convert string type variable to int and do equation on flutter?

Question

I fetched the amount from firestore, And in the UI has text field user can add value to that text field that also string I want summation both that "(oneAmount?.amount)! + (amountController.text)"

code

void displayMessage() {
    if (amountController.text != null) {
      int amount = ((oneAmount?.amount)! + (amountController.text)) as int;

      FirebaseFirestore.instance
          .collection("recharge")
          .doc("${loggedInUser.uid}")
          .set({
        "amount": amount,
      });
      Navigator.push(
        context,
        MaterialPageRoute(builder: (context) => const HomeScreen()),
      );
    } else {}
}

Does this answer your question? [How do I parse a string into a number with Dart?](https://stackoverflow.com/questions/13167496/how-do-i-parse-a-string-into-a-number-with-dart) — OMi Shah, Nov 02 '22 at 16:28
parse it to int like this int.parse(amountController.text).toInt() — 7eg, Nov 02 '22 at 17:12

score 1 · Accepted Answer · answered Nov 02 '22 at 16:21

1

you should parse the string into int before doing the addition.

Example

int amount = (int.tryParse(oneAmount?.amount) ?? 0) + (int.tryParse(amountController.text) ?? 0);

answered Nov 02 '22 at 16:21

Sujan Gainju

4,273
2
14
34

score 1 · Answer 2 · answered Nov 02 '22 at 17:15

1

initialize an int like below:

int a =   int.parse(amountController.text).toInt();

Then use the int a in your addition

int amount = ((oneAmount?.amount)! + (a));

answered Nov 02 '22 at 17:15

7eg

285
3
11

How to convert string type variable to int and do equation on flutter?

2 Answers2