hasOwnProperty < Object < JavaScript

The hasOwnProperty() method of Object instances returns a boolean indicating whether the object has the specified property as its own property or not.

    
    const account = {
        amount: 100
    }

    const accountObjHasOwnPropAmount = account.hasOwnProperty('amount');

    console.log(accountObjHasOwnPropAmount);
    // true

    console.log(account.hasOwnProperty('toString'));
    // false