Nodejs Base64 Encode toBase64()

Method Source Code

var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'.split('');
String.prototype.toBase64 = function() {
  var encoded = [];
  var a, b, c;//from  w ww .j  a  va  2  s  .co m
  for (var i = 0, len = this.length; i < len; i = i + 3) {
    a = this.charCodeAt(i);
    encoded.push(code[a >> 2]);

    b = this.charCodeAt(i + 1);
    if (isNaN(b)) {
      encoded.push(code[(a & 3) << 4]);
      encoded.push('=', '=');
    }
    else {
      encoded.push(code[(a & 3) << 4 | b >> 4]);

      c = this.charCodeAt(i + 2);
      if (isNaN(c)) {
        encoded.push(code[(b & 15) << 2]);
        encoded.push('=');
      }
      else {
        encoded.push(code[(b & 15) << 2 | c >> 6]);
        encoded.push(code[c & 63]);
      }
    }
  }

  return encoded.join('');
}

Related

1. toBase64(()

   String.prototype.toBase64 = (function(){
     var b64chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
     var b64hash = {}; b64chars.split('').forEach(function(v,i){b64hash[v]=i});
     var b64pos = [18, 12, 6, 0];
     var b64and = b64pos.map(function(v){return 63<<v});
     return function toBase64 () {
       var length = this.length;
       var count, encoded = [], b64string = "";
       var i, extra;
   ...
   

2. toBase64()

   String.prototype.toBase64 = function () {
       var converter = new Buffer(this.toString(), 'utf8');
       return converter.toString('base64');
   

3. toBase64()

   const CODES = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='
   String.prototype.toBase64 = function() {
     let out = ''
     for (let i = 0, length = this.length; i < length; i += 3) {
       let [a, b, c] = [...this.slice(i, i + 3)].map(c => c.charCodeAt(0))
       bits = a << 16 | b << 8 | c
       out += CODES[bits >> 18 & 0x3F]
       out += CODES[bits >> 12 & 0x3F]
       out += b ? CODES[bits >> 6 & 0x3F] : '='
   ...
   

4. toBase64()

   String.prototype.toBase64 = function() {
     var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
     var output = ""
     var chr1, chr2, chr3
     var enc1, enc2, enc3, enc4
      var i = 0
      do {
         chr1 = this.charCodeAt(i++)
         chr2 = this.charCodeAt(i++)
   ...
   

5. toBase64()

   String.prototype.toBase64 = function(){
     var nToOrd = function(n){
       return n < 26 ? "A".charCodeAt(0) + n : (
         n < 52 ? "a".charCodeAt(0) - 26 + n : (
           n < 62 ? "0".charCodeAt(0) - 52 + n : (
             n==62 ? "+".charCodeAt(0) : "/".charCodeAt(0)
           )
         )
       );
   ...
   

6. toBase64()

   String.prototype.toBase64 = function() {
     var chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
     var encoded = '';
     for(var i=0; i < this.length; i+=3) {
       var c1 = this.charCodeAt(i),
           c2 = this.charCodeAt(i+1),
           c3 = this.charCodeAt(i+2);
       encoded += chars[(c1 & 0xFC) >> 2];
       encoded += chars[((c1 & 0x03) << 4) | ((c2 & 0xF0) >> 4)];
   ...
   

7. toBase64()

   String.prototype.toBase64 = function () {
     var stringyBits = this.match(/.{1,3}/g);
     var alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".split("");
     result = stringyBits.map(function(threeLetters) {
      var letters = threeLetters.split("");
       var ascii3 = letters.map(function(char) {
         return pad(char.charCodeAt(0).toString(2),8);
       });
       var twentyFour3 = ascii3[0]+ascii3[1]+ascii3[2];
   ...