What's the detailed explanation for why the 1st function is correct and the 2nd is wrong?

[Atman Atos]

I understand that there are many easier and shorter ways of solving it but I want to grasp the concept behind the 2nd function in such a scenario. Solutions should be in the 2nd function format only and should be accompanied by a detailed explanation.

The logic

• I have an array of objects representing different people in a contacts list.
• The function should check if name 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 name does not correspond to any contacts then return the string No such contact.
• If prop does not correspond to any valid properties of a contact found to match name then return the string No such property.

The object array const contacts = [ { firstName: "Akira", lastName: "Laine", number: "0543236543", likes: ["Pizza", "Coding", "Brownie Points"], }, { firstName: "Harry", lastName: "Potter", number: "0994372684", likes: ["Hogwarts", "Magic", "Hagrid"], } ]


1st function (Correct)

function lookUpProfile(name, prop) {


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


lookUpProfile("Akira", "likes");


2nd function (wrong)

function lookUpProfile(name, prop) {


for (let x = 0; x < contacts.length; x++) { if (name === contacts[x].firstName && contacts[x].hasOwnProperty(prop)) { return contacts[x][prop]; } if (name !== contacts[x].firstName || contacts[x].lastName) { return "No such contact"; } if (prop !== contacts[x][prop].name) { return "No such property"; } } }


lookUpProfile("Akira", "likes");

 

[MeMate]

Nobody can read that. Please format your code within code tags. Don't expect efford from us if you're not ready to put effort by yourself in it. At least you need help from us. Not the other way around. Sorry but this has to be said.

 

[Atman Atos]

I wish to edit the codes above but I can't find the edit button, hence I have rewritten them. Between the time of posting the original question and now, I have figured out that one reason the 2nd function might be faulty is that I am referencing properties that don't exist. i.e, if (prop !== contacts[x][prop].name). If there's a way the 2nd function can be modified, retaining the use of !== operator, kindly share such functional modification.

The object array

array const contacts = [ { firstName: "Akira", lastName: "Laine", number: "0543236543", likes: ["Pizza", "Coding", "Brownie Points"], }, { firstName: "Harry", lastName: "Potter", number: "0994372684", likes: ["Hogwarts", "Magic", "Hagrid"], } ]

1st function (correct)

function lookUpProfile(name, prop) {


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


lookUpProfile("Akira", "likes");

2nd function (wrong)

function lookUpProfile(name, prop) {


for (let x = 0; x < contacts.length; x++) { if (name === contacts[x].firstName && contacts[x].hasOwnProperty(prop)) { return contacts[x][prop]; } if (name !== contacts[x].firstName || contacts[x].lastName) { return "No such contact"; } if (prop !== contacts[x][prop].name) { return "No such property"; } } }


lookUpProfile("Akira", "likes");

 

[Padonak]

function lookUpProfile(name, prop){
           for(let x of contacts){
             if(x.firstName !== name && x.lastName !== name){
               return "No such contact";
             }
             if(!x[prop]){
               return "No such property";
             }
             return x[prop];
            }
          }


         console.log( lookUpProfile("Akira", "likes") ); // ['Pizza', 'Coding', 'Brownie Points']
         console.log( lookUpProfile("Akita", "likes") ); // No such contact
         console.log( lookUpProfile("Akira", "lacks") ); // No such property