实现String转bytes属性扩展

String.prototype.toBytes = function () {
var ch, st, re = [];
for (var i = 0; i < this.length; i++) {
ch = this.charCodeAt(i); // get char
st = []; // set up "stack"
do {
st.push(ch & 0xFF); // push byte to stack
ch = ch >> 8; // shift value down by 1 byte
}
while (ch);
// add stack contents to result
// done because chars have "wrong" endianness
re = re.concat(st.reverse());
}
// return an array of bytes
return re;
}