Checkpoint: Profile Lookup

Instructions

We have an array of objects representing different people in our contacts lists.

A lookUp function that takes firstName and a property (prop) as arguments has been pre-written for you.

The function should check if firstName is an actual contact's firstName and the given property (prop) is a property of that contact.

If both are true, then return the "value" of that property.

If firstName does not correspond to any contacts then return "No such contact"

If prop does not correspond to any valid properties then return "No such property"

Remember to use Read-Search-Ask if you get stuck. Try to pair program. Write your own code.

Useful Links

• Challenge: Accessing Objects Properties with Bracket Notation
• Challenge: Iterate with JavaScript For Loops

Problem Explanation:

• Change the code below // Only change code below this line and up to // Only change code above this line
• Take note that you are editing the inside of the lookUp function
  • This function includes two parameters, firstName and prop
• The function should check look through the contact list for the given firstName parameter
  • If there is a match found, the function should then look for the given prop parameter
  • If both firstName and the associated prop are found, you should return the value of the prop
  • If firstName is found and no associated prop is found, you should return "No such property"
  • If firstName isn't found anywhere, you should return "No such contact"

Hint: 1

• Use a for loop to cycle through the contact list

Hint: 2

• Use a nested if statement to first check if the firstName matches, and then checks if the prop matches

Hint: 3

• Leave your return "No such contact" out of the for loop as a final catch-all

Spoiler Alert!

Solution ahead!

Code Solution:

for (var x = 0; x < contacts.length; x++){
    if (contacts[x].firstName === firstName) {
        if (contacts[x][prop]) {
            return contacts[x][prop];
        } else {
            return "No such property";
        }
    }
}
return "No such contact";

Code Explanation:

• The for loop runs, starting at the first object in the contacts list
• If the firstName parameter passed into the function matches the value of the "firstName" key in the first object, the if statement passes
• Then, if the prop parameter passed into the function is present in that object, the value of the prop is returned
  • If the second if statement fails, "No such property" is returned
• If the first if statement fails, the for loop continues on to the next object in the contact list
• If the firstName parameter isn't matched by the final contact object, the for loop exits and "No such contact" is returned

Example Run

• lookUp("Akira","likes"); runs
• "Akira" is matched to the "firstName" key in the first object, so the if statement returns true
• "likes" is found within the first object, so the second if statement returns true
• The value of "likes" is returned - "Pizza", "Coding", "Brownie Points"

Credits:

If you found this page useful, you can give thanks by copying and pasting this on the main chat: thanks @leftynaut for your help with Checkpoint: Profile Lookup

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