function stringToBytes(s: string): Uint8Array {
        let arr = new Uint8Array(s.length);
        for (let i = 0, l = s.length; i < l; i++) {
            arr[i] = s.charCodeAt(i);
        }
        return arr;
    };

    // ASCII only
    function bytesToString(buffer: ArrayBuffer): string {
        return String.fromCharCode.apply(null, new Uint8Array(buffer));
    };

    function byteArrayToLong( /*byte[]*/ buff: ArrayBuffer): number {
        var byteArray = new Uint8Array(buff)
        var value = 0;
        for (let i = byteArray.length - 1; i >= 0; i--) {
            value = (value * 256) + byteArray[i];
        }
        return value;
    };
    
    function byteArrayToLong( /*byte[]*/ buff) {
    var byteArray = new Uint8Array(buff)
    var value = 0;
    for (var i = byteArray.length - 1; i >= 0; i--) {
        value = (value * 256) + byteArray[i];
    }
    return value;
};

寫法2:

function Buf2Str(buf) {
    let ss = "< ";
    buf.forEach(b => { ss += b.toString(16) + ' '; });
    return ss + ">";
}