byteLength.js

var str = '\u00bd + \u00bc = \u00be';

console.log(str + ": " + str.length + " characters, " +
          Buffer.byteLength(str, 'utf8') + " bytes");

// ½ + ¼ = ¾: 9 characters, 12 bytes
var buf = new Buffer(256);
var len = buf.write('\u00bd + \u00bc = \u00be', 0);
console.log(len + " bytes: " + buf.toString('utf8', 0, len));

str = "node.js";
buf = new Buffer(str.length);

for (var i = 0; i < str.length ; i++) {
      buf[i] = str.charCodeAt(i);
}
console.log(buf);

var buf = new Buffer(4);

buf[0] = 0x3;
buf[1] = 0x4;
buf[2] = 0x23;
buf[3] = 0x42;

//for (var ii = 0; ii < buf.length; ii++) {
//    console.log(buf.readUInt8(ii));
//}

var buf = new Buffer(4);

buf[0] = 0x3;
buf[1] = 0x4;
buf[2] = 0x23;
buf[3] = 0x42;

console.log(buf.readUInt16BE(0));
console.log(buf.readUInt16LE(0));
console.log(buf.readUInt16BE(1));
console.log(buf.readUInt16LE(1));
console.log(buf.readUInt16BE(2));
console.log(buf.readUInt16LE(2));

var buf = new Buffer(4);

buf[0] = 0x00;
buf[1] = 0x00;
buf[2] = 0x80;
buf[3] = 0x3f;

console.log(buf.readFloatLE(0));