[Java] Stream Api--reduce

Aggregation operations reduce

t reduce (t identity, Binaryoperator Accumulator)

Code:

int value = Stream.of (1, 2, 3, 4). Reduce (sum, item), sum + item);

Or use a method reference:

int value = Stream.of (1, 2, 3, 4). Reduce (+, integer::sum);

Value results: 101,103,106,110

Identity: It allows the user to provide an initial value for a loop calculation. (+)

ACCUMULATOR: The computed accumulator, whose method signature is apply (T t,u u), in which the first parameter T(SUM) is the return value of the last function calculation, the second parameter U(item) As the element in the stream, this function calculates the two values for apply, and the resulting and assigned values are assigned to the first parameter of the next execution of this method

[Java] Stream Api--reduce