缓冲区：Nodejs

   const buf = buffer.from('hello');

   const buf = buffer.alloc(10); // 10-byte buffer filled with zeros

   const buf = buffer.from([72, 101, 108, 108, 111]); // represents 'hello'

   const buf = buffer.from('hello');
   console.log(buf.tostring()); // 'hello'

   const buf = buffer.from('hello');
   console.log(buf.length); // 5 (each character takes 1 byte)

   const buf = buffer.alloc(5);
   buf.write('hi');
   console.log(buf.tostring()); // 'hi'

   const buf = buffer.from('hello world');
   const slice = buf.slice(0, 5);
   console.log(slice.tostring()); // 'hello'

   const buf1 = buffer.from('hello');
   const buf2 = buffer.alloc(5);
   buf1.copy(buf2);
   console.log(buf2.tostring()); // 'hello'

   const buf1 = buffer.from('abc');
   const buf2 = buffer.from('abc');
   console.log(buf1.equals(buf2)); // true

   const buf1 = Buffer.from('Hello');
   const buf2 = Buffer.from(' World');
   const buf3 = Buffer.concat([buf1, buf2]);
   console.log(buf3.toString()); // 'Hello World'