Profile Lookup Challange accessing problem

Profile Lookup Challange accessing problem
0

#1

Tell us what’s happening:

I can’t access the property ‘prop’ value by contacts[i].prop but contacts[i][prop] works fine. Why is this happening? As far as i know, ‘[ ]’ can be equivalently used in place of ‘.’ for accessing the objects or arrays.

Your code so far

//Setup
var contacts = [
    {
        "firstName": "Akira",
        "lastName": "Laine",
        "number": "0543236543",
        "likes": ["Pizza", "Coding", "Brownie Points"]
    },
    {
        "firstName": "Harry",
        "lastName": "Potter",
        "number": "0994372684",
        "likes": ["Hogwarts", "Magic", "Hagrid"]
    },
    {
        "firstName": "Sherlock",
        "lastName": "Holmes",
        "number": "0487345643",
        "likes": ["Intriguing Cases", "Violin"]
    },
    {
        "firstName": "Kristian",
        "lastName": "Vos",
        "number": "unknown",
        "likes": ["Javascript", "Gaming", "Foxes"]
    }
];


function lookUpProfile(firstName, prop)
{
// Only change code below this line
  var flag1=0, flag2=0;
  var p;
  for(var i=0;i<contacts.length;i++)
  {
    if(contacts[i].firstName===firstName)
      {
         flag1=1; 
          if(contacts[i].hasOwnProperty(prop))
           {
             flag2=1;
             p=contacts[i][prop];
             
           }
           
      }
  }
           
          if(flag2===1)
          {
            return p;
          }
          else if(flag1===1)
          {
            return "No such property";
          }
          else
          {
            return "No such contact";
          }
// Only change code above this line
}

// Change these values to test your function
lookUpProfile("Kristian", "lastName");

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36.

Link to the challenge:


#2

If I understand your question correctly, you are using contacts[i].prop instead of contacts[i].lastName.

The reason contacts[i][prop] is valid because it is same as typing contacts[i]['lastName'] or typing contacts[i].lastName.
Here prop is being used as a variable that has the string 'lastName'.

Whereas contacts[i].prop is looking for the value of prop; which contact[i] has no such property.


#3

You may want to review the following three FCC challenges regarding accessing properties via dot and bracket notation. The 3rd one deals with using a variable to access an object’s property.