Question

Is there a way to set every element of a Javascript typed array (i.e. a Uint32Array) to some value (something like the C function memset would do)?

var foo = new Uint32Array(16384);
for (int i=0; i<foo.length; i++) {   // I want to do this without a for-loop
    foo[i] = 0xdeadbeef;
}

Answer 1

Generally, the answer in this case is going to be no. In JavaScript you either declare things fully when you create them via literal syntax:

var Arr1 = [1,2,3,4,5];

Or you assign values to them (via loops when necessary for sequences):

var Arr2 = Array(32);

for (var i = 0, j < Arr2.length; i < j; ++i) { Arr2[i] = 0xdeadbeef; }

JavaScript is a language that benefits from only accessing Arr2.length once when possible, so this syntax should net a performance benefit over other variations, but there’s not a way to assign all positions in an array to a specific value other than undefined, which is what you get when you initialize with a size.