Uncaught Type error: undefined is not a function while creating an object

Question

Base64.js

var Base64 = {
  _keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
  encode: function(e) {
    var t = "";
    var n, r, i, s, o, u, a;
    var f = 0;
    e = Base64._utf8_encode(e);
    while (f < e.length) {
      n = e.charCodeAt(f++);
      r = e.charCodeAt(f++);
      i = e.charCodeAt(f++);
      s = n >> 2;
      o = (n & 3) << 4 | r >> 4;
      u = (r & 15) << 2 | i >> 6;
      a = i & 63;
      if (isNaN(r)) {
        u = a = 64
      } else if (isNaN(i)) {
        a = 64
      }
      t = t + this._keyStr.charAt(s) + this._keyStr.charAt(o) + this._keyStr.charAt(u) + this._keyStr.charAt(a)
    }
    return t
  }
}

I am calling encode method from another file like below had imported base64.js file and created object

Var base64=new Base64.encode(input);

Error:

Uncaught Type error: undefined is not a function

Can any one help?

Answer 1

Errors in your code:

1. Var should be var
2. _utf8_encode is not defined.
3. You are returning encoded string. You do not need to create object. Just do var encodedStr = Base64.encode(input)

4. In this line

    t = t + this._keyStr.charAt(s) + this._keyStr.charAt(o) + this._keyStr.charAt(u) + this._keyStr.charAt(a) 

   in your original code, this refers to the object created by new , not Base64 , so this._keyStr is undefined . But if you directly call Base64.encode() (#3 above), it will refer to Base64 and you will get proper values.

 var Base64 = { _keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=", encode: function(e) { var t = ""; var n, r, i, s, o, u, a; var f = 0; e = Base64._utf8_encode(e); while (f < e.length) { n = e.charCodeAt(f++); r = e.charCodeAt(f++); i = e.charCodeAt(f++); s = n >> 2; o = (n & 3) << 4 | r >> 4; u = (r & 15) << 2 | i >> 6; a = i & 63; if (isNaN(r)) { u = a = 64 } else if (isNaN(i)) { a = 64 } t = t + this._keyStr.charAt(s) + this._keyStr.charAt(o) + this._keyStr.charAt(u) + this._keyStr.charAt(a) } return t }, _utf8_encode: function(e) { // do your processing return e } } var input = "Hello World"; var base64 = Base64.encode(input); console.log(base64) 

Rectified JSFiddle

Note: I have defined _utf8_encode , but it returns same text. Please add necessary code.