Testing Objects for Properties_2

JavaScript
#1

Tell us what’s happening:
Once again, I’m having trouble with the logic. First, I wasn’t sure whether to put quotes within the hasOwnProperty function. (method) When I removed the quotes, I kept getting undefined, so I put them back. The return value with quotes is always Not Found.

Your code so far


// Setup
var myObj = {
  gift: "pony",
  pet: "kitten",
  bed: "sleigh"
};

function checkObj(checkProp) {
 if(myObj.hasOwnProperty("checkProp"))   
{
   return myObj.checkProp;
 } 
  
  return "Not Found";
}

// Test your code by modifying these values
checkObj("gift");

// Test your code by modifying these values
checkObj("gift");

/* TEST RESULTS
// running test
checkObj(“gift”) should return “pony”.
checkObj(“pet”) should return “kitten”.
// tests completed
*/
Your browser information:

User Agent is: Chrome/68.0.3440.75 .

Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/basic-javascript/testing-objects-for-properties

#2

When you write myObj.hasOwnProperty(“checkProp”), you are asking if myObj has an actual property named “checkProp”. Remember, checkProp is a variable. It contains a string, so you can just reference checkProp without the quotes around it.

You can not use dot notation to access an object’s property with a variable. Review your previous lessons on how to do this properly.

#3

This is what I did, and it worked, but I have a couple of questions:

  1. Is this the best way to do this lesson? It seems like you should be able to put checkProp directly in the brackets since both checkProp, v1, & v2 are all variables. Any explanation for this? Thank you for your help.

‘’’
// Setup
var myObj = {
gift: “pony”,
pet: “kitten”,
bed: “sleigh”
};

function checkObj(checkProp) {
if(myObj.hasOwnProperty(checkProp)){
var v1 = checkProp;
var v2 = myObj[v1];
return v2;
}

return "Not Found";

}

// Test your code by modifying these values
console.log(checkObj(“pet”));
‘’’

#4

if you did myObj[checkProp] I believe it returns undefined if the object doesn’t exist.

#5

I know that but why?? Thanks for the reply.

#6

Not sure how to answer it other than to say because it doesn’t exist. If js doesn’t find something to return, it usually returns an undefined or something similar.

#7

I will say that you should google “falsy javascript”. It may help answer your questions.

#8

Okay, thanks. (bla, bla.)

#9