determining range of values of TypedArray item

Question

According to the documentation on the Uint8ClampedArray,

The Uint8ClampedArray typed array represents an array of 8-bit unsigned integers clamped to 0-255; if you specified a value that is out of the range of [0,255], 0 or 255 will be set instead.

Other TypedArrays function similarly. Given any typed array amongst the types listed, is there a way to programmatically derive the max/min value possible to store therein?

Something along the lines of:

Uint8ClampedArray().maxItemValue // returns 255

Answer 1

I'd use the following:

function maxElementValue(arr) {
    const c = arr.constructor;
    const test = c.of(-1.5)[0];
    if (test > 0) // unsigned integers
        return test;
    //  return 0xFFFFFFFF >>> (32 - 8 * c.BYTES_PER_ELEMENT);
    //  return Math.pow(2, 8 * c.BYTES_PER_ELEMENT) - 1;
    if (test == -1) // signed integers
        return 0x7FFFFFFF >>> (32 - 8 * c.BYTES_PER_ELEMENT);
    //  return Math.pow(2, 8 * c.BYTES_PER_ELEMENT - 1) - 1;
    if (test == 0) // clamped
        return 0xFF; // there's only one of these
    if (test == -1.5)
        throw new TypeError("floats are not supported");
    throw new TypeError("weirdly behaving typed array");
}