this.js

var someObj = {

  someMethod: function() {
    this.someProp = 'huzzah!';
    console.log(this);
    // this refers to someObj:
    // { ..., someProp: 'huzzah!' }

    someNestedFunction();

    function someNestedFunction() {
      console.log(this);
      // this now refers to someNestedFunction context,
      // which is different than someObj

      // Solution? var self = this (outside the nested function)
      // self will always refer to someObj context
    }
  }
}

someObj.someMethod();