How to use a function to set a value in a ternary operation?-CodePudding

There are 3 values,

previousBalanceTotal = It is the total balance in a bank account
previousWithdrawTotal = I've withdrawn this much total value before
newWithdrawAmount = The amount I want to withdraw now,

I need to set newWithdrawTotal now.

What i wanna do is, if my newWithdrawAmount is bigger than my previousBalanceTotal, I want to show an alert, and keep the newWithdrawTotal as previousWithdrawTotal, else add the newWithdrawAmount to previousWithdrawTotal and keep it in newWithdrawTotal.

I tried the following code, but it does not work when newWithdrawAmount is greater than previousBalanceTotal. It returns a function and doesn't show the alert. Could you please help me to solve this??

const newWithdrawTotal = (newWithdrawAmount < previousBalanceTotal) ? (newWithdrawAmount   previousWithdrawTotal) : function () {
    console.log(previousWithdrawTotal);

    alert('you can not withdraw more than your balance');
    return previousWithdrawTotal;
};
console.log(newWithdrawTotal);

CodePudding user response：

You're not calling the function, you're just returning it. Use an IIFE to call the anonymous function immediately.

const newWithdrawTotal = (newWithdrawAmount < previousBalanceTotal) ?
  (newWithdrawAmount   previousWithdrawTotal) : (function() {
    console.log(previousWithdrawTotal);

    alert('you can not withdraw more than your balance');
    return previousWithdrawTotal;
  })();
console.log(newWithdrawTotal);

You don't really need the function, you can use the comma-operator instead.

const newWithdrawTotal = (newWithdrawAmount < previousBalanceTotal) ? (newWithdrawAmount   previousWithdrawTotal) : (
  console.log(previousWithdrawTotal),
  alert('you can not withdraw more than your balance'),
  previousWithdrawTotal
);

console.log(newWithdrawTotal);

CodePudding user response：

Try this code block

const newWithdrawAmount = 13000;
const previousBalanceTotal = 12000;
const previousWithdrawTotal = 300;
var newWithdrawTotal;
function calc() {
    if(newWithdrawAmount < previousBalanceTotal) {
        return newWithdrawTotal = newWithdrawAmount   previousWithdrawTotal
    } else {
        console.log(previousWithdrawTotal);
        alert('you can not withdraw more than your balance');
        return newWithdrawTotal = previousWithdrawTotal;
    }
}
calc()
console.log(newWithdrawTotal);