Instructions for the buffer.toString method in node.js

method description:

Converts the buffer object to the specified character-encoded string.

syntax:

buffer.toString([encoding], [start], [end])

receive parameters:

encoding             the character encoding converted to a string, which defaults to 'utf8'

start                         buffer conversion starts at the default position of 0

end                      

  buffer end of conversion, buffer length

by default

example:

var b = new Buffer(50);

 

console.log(b);

 

var c = b.toString('base64',0,10);

 

console.log(c);

source code:

// toString(encoding, start=0, end=buffer.length)

Buffer.prototype.toString = function(encoding, start, end) {

  var loweredCase = false;

  start = start >>> 0;

  end = util.isUndefined(end) ? this.length : end >>> 0;

  if (!encoding) encoding = 'utf8';

  if (start < 0) start = 0;

  if (end > this.length) end = this.length;

  if (end <= start) return '';

  while (true) {

    switch (encoding) {

      case 'hex':

        return this.hexSlice(start, end);

      case 'utf8':

      case 'utf-8':

        return this.utf8Slice(start, end);

      case 'ascii':

        return this.asciiSlice(start, end);

      case 'binary':

        return this.binarySlice(start, end);

      case 'base64':

        return this.base64Slice(start, end);

      case 'ucs2':

      case 'ucs-2':

      case 'utf16le':

      case 'utf-16le':

        return this.ucs2Slice(start, end);

      default:

        if (loweredCase)

          throw new TypeError('Unknown encoding: ' + encoding);

        encoding = (encoding + '').toLowerCase();

        loweredCase = true;

    }

  }

};