repl.txt (1309B)
1 2 {{alias}}( collection, initial, reducer[, thisArg] ) 3 Applies a function against an accumulator and each element in a collection 4 and returns the accumulated result, iterating from right to left. 5 6 When invoked, the reduction function is provided four arguments: 7 8 - `accumulator`: accumulated value 9 - `value`: collection value 10 - `index`: collection index 11 - `collection`: the input collection 12 13 If provided an empty collection, the function returns the initial value. 14 15 Parameters 16 ---------- 17 collection: Array|TypedArray|Object 18 Input collection. If provided an object, the object must be array-like 19 (excluding strings and functions). 20 21 initial: any 22 Accumulator value used in the first invocation of the reduction 23 function. 24 25 reducer: Function 26 Function to invoke for each element in the input collection. 27 28 thisArg: any (optional) 29 Execution context. 30 31 Returns 32 ------- 33 out: any 34 Accumulated result. 35 36 Examples 37 -------- 38 > function sum( acc, v ) { 39 ... console.log( '%s: %d', acc, v ); 40 ... return acc + v; 41 ... }; 42 > var arr = [ 1.0, 2.0, 3.0 ]; 43 > var out = {{alias}}( arr, 0, sum ); 44 2: 3.0 45 1: 2.0 46 0: 1.0 47 > out 48 6.0 49 50 See Also 51 -------- 52