Sum

Description:

This method returns total of the value in a sequence, The first overload (without any argument) is used for a collation that contains only numeric values.

It also accepts an argument as a selector that selects property of items to be used in some method. That property should be a numeric only.

Samples:

let numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 15, 19];

let stock = [
  { name: 'Apple', category: 'Fruit', price: 0.30 },
  { name: 'Banana', category: 'Fruit', price: 0.35 },
  { name: 'Orange', category: 'Fruit', price: 0.29 },
  { name: 'Cabbage', category: 'Vegetable', price: 0.49 },
  { name: 'Carrot', category: 'Vegetable', price: 0.29 },
  { name: 'Lettuce', category: 'Vegetable', price: 0.30 },
  { name: 'Milk', category: 'Dairy', price: 1.12 }
];

let sum = numbers.asEnumerable().sum();
console.log('sum => ' + sum);

sum = stock.asEnumerable().sum(item => item.price);
console.log('total of stock items price => ' + sum);