phpjs/_octopress/source/functions/quoted_printable_encode/index.markdown

php.js offers community built php functions in javascript

---
layout: page
title: "JavaScript quoted_printable_encode function"
comments: true
sharing: true
footer: true
alias:
- /functions/view/quoted_printable_encode:835
- /functions/view/quoted_printable_encode
- /functions/view/835
- /functions/quoted_printable_encode:835
- /functions/835
---
<!-- Generated by Rakefile:build -->
A JavaScript equivalent of PHP's quoted_printable_encode

{% codeblock strings/quoted_printable_encode.js lang:js https://raw.github.com/kvz/phpjs/master/functions/strings/quoted_printable_encode.js raw on github %}
function quoted_printable_encode (str) {
  // +   original by: Theriault
  // +   improved by: Brett Zamir (http://brett-zamir.me)
  // +   improved by: Theriault
  // *     example 1: quoted_printable_encode('a=b=c');
  // *     returns 1: 'a=3Db=3Dc'
  // *     example 2: quoted_printable_encode('abc   \r\n123   \r\n');
  // *     returns 2: 'abc  =20\r\n123  =20\r\n'
  // *     example 3: quoted_printable_encode('0123456789012345678901234567890123456789012345678901234567890123456789012345');
  // *     returns 3: '012345678901234567890123456789012345678901234567890123456789012345678901234=\r\n5'
  // RFC 2045: 6.7.2: Octets with decimal values of 33 through 60 (bang to less-than) inclusive, and 62 through 126 (greater-than to tilde), inclusive, MAY be represented as the US-ASCII characters
  // PHP does not encode any of the above; as does this function.
  // RFC 2045: 6.7.3: Octets with values of 9 and 32 MAY be represented as US-ASCII TAB (HT) and SPACE characters, respectively, but MUST NOT be so represented at the end of an encoded line
  // PHP does not encode spaces (octet 32) except before a CRLF sequence as stated above. PHP always encodes tabs (octet 9). This function replicates PHP.
  // RFC 2045: 6.7.4: A line break in a text body, represented as a CRLF sequence in the text canonical form, must be represented by a (RFC 822) line break
  // PHP does not encode a CRLF sequence, as does this function.
  // RFC 2045: 6.7.5: The Quoted-Printable encoding REQUIRES that encoded lines be no more than 76 characters long. If longer lines are to be encoded with the Quoted-Printable encoding, "soft" line breaks must be used.
  // PHP breaks lines greater than 76 characters; as does this function.
  var hexChars = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'],
    RFC2045Encode1IN = / \r\n|\r\n|[^!-<>-~ ]/gm,
    RFC2045Encode1OUT = function (sMatch) {
      // Encode space before CRLF sequence to prevent spaces from being stripped
      // Keep hard line breaks intact; CRLF sequences
      if (sMatch.length > 1) {
        return sMatch.replace(' ', '=20');
      }
      // Encode matching character
      var chr = sMatch.charCodeAt(0);
      return '=' + hexChars[((chr >>> 4) & 15)] + hexChars[(chr & 15)];
    },
    // Split lines to 75 characters; the reason it's 75 and not 76 is because softline breaks are preceeded by an equal sign; which would be the 76th character.
    // However, if the last line/string was exactly 76 characters, then a softline would not be needed. PHP currently softbreaks anyway; so this function replicates PHP.
    RFC2045Encode2IN = /.{1,72}(?!\r\n)[^=]{0,3}/g,
    RFC2045Encode2OUT = function (sMatch) {
      if (sMatch.substr(sMatch.length - 2) === '\r\n') {
        return sMatch;
      }
      return sMatch + '=\r\n';
    };
  str = str.replace(RFC2045Encode1IN, RFC2045Encode1OUT).replace(RFC2045Encode2IN, RFC2045Encode2OUT);
  // Strip last softline break
  return str.substr(0, str.length - 3);
}
{% endcodeblock %}

 - [Raw function on GitHub](https://github.com/kvz/phpjs/blob/master/functions/strings/quoted_printable_encode.js)

Please note that php.js uses JavaScript objects as substitutes for PHP arrays, they are 
the closest match to this hashtable-like data structure. 

Please also note that php.js offers community built functions and goes by the 
[McDonald's Theory](https://medium.com/what-i-learned-building/9216e1c9da7d). We'll put online 
functions that are far from perfect, in the hopes to spark better contributions. 
Do you have one? Then please just: 

 - [Edit on GitHub](https://github.com/kvz/phpjs/edit/master/functions/strings/quoted_printable_encode.js)

### Example 1
This code
{% codeblock lang:js example %}
quoted_printable_encode('a=b=c');
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
'a=3Db=3Dc'
{% endcodeblock %}

### Example 2
This code
{% codeblock lang:js example %}
quoted_printable_encode('abc   \r\n123   \r\n');
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
'abc  =20\r\n123  =20\r\n'
{% endcodeblock %}

### Example 3
This code
{% codeblock lang:js example %}
quoted_printable_encode('0123456789012345678901234567890123456789012345678901234567890123456789012345');
{% endcodeblock %}

Should return
{% codeblock lang:js returns %}
'012345678901234567890123456789012345678901234567890123456789012345678901234=\r\n5'
{% endcodeblock %}


### Other PHP functions in the strings extension
{% render_partial _includes/custom/strings.html %}