sumByValue method
Calculates the sum of a list of objects based on a specific property value.
The selector function retrieves the property value to be summed for each element.
The property value can be either a string or a number.
Returns the sum as a string representation.
Example:
List<MyObject> myList = [
MyObject(5),
MyObject(10),
MyObject(3),
];
int sum = myList.sumByValue((obj) => obj.value);
print(sum); // Output: 18
Implementation
double sumByValue(num Function(T) selector) {
double total = 0;
for (T e in this) {
num value = selector(e);
total += value;
}
return total;
}