How do I multiply each member of an array by a scalar in javascript?

Question

For example, how do I achieve the following without iterating over the array?

var a = [1, 2, 3] * 5;  // a should equal [5, 10, 15]

Answer 1

Ecmascript 2016 (ES7) defines SIMD mathematics which allow to do multiplications like the one you desire faster and easier. However, as of today there is very little browser support for SIMD (only Firefox nightly builds support this) [1], [2]. This is how it will look like:

var a = SIMD.Float32x4(1, 2, 3);
var b = SIMD.Float32x4(5, 5, 5);
SIMD.Float32x4.mul(a, b);  // Float32x4[5, 10, 15]

Until there will be widespread support for SIMD you'd have to resort to using map

var a = [1, 2, 3].map(function(x) { return x * 5; });

which is nicely supported by all modern browsers [3].