Buffer、ArrayBuffer互轉

//方法1
//Buffer轉ArrayBuffer
function toArrayBuffer(buf) {
    var ab = new ArrayBuffer(buf.length);
    var view = new Uint8Array(ab);
    for (var i = 0; i < buf.length; ++i) {
        view[i] = buf[i];
    }    
    return ab;        
}

//ArrayBuffer轉Buffer
function toBuffer(ab) {
    var buf = new Buffer(ab.byteLength);
    var view = new Uint8Array(ab);
    for (var i = 0; i < buf.length; ++i) {
        buf[i] = view[i];
    }
    return buf;
}

//方法2
// Buffer轉ArrayBuffer
const buf = Buffer.from("this is a test");
console.log(buf);
console.log(buf.toString());
var arrayBuf = buf.buffer; //Buffer的buffer屬性返回arrayBuf
console.log(arrayBuf);

//ArrayBuffer轉Buffer
var arrayBuffer = new ArrayBuffer(16);
const buffer = Buffer.from(arrayBuffer);
console.log(buffer.buffer === arrayBuffer);