examineNaN.js

function examineNaN(x) {
    const buf = new ArrayBuffer(8);
    const view = new DataView(buf);

    view.setFloat64(0, x);

    let binStr = '';
    for (let i = 0; i < 8; i++) {
        binStr += ('00000000' + view.getUint8(i).toString(2)).slice(-8) + ' ';
    }
    return binStr
}