How can I write this function with a forEach loop?

Question

So I'm working on a FreeCodeCamp javascript problem. I was able to write a working function using a for loop, but when I try to write the same function with a forEach loop, it doesn't work. How can I get it to work?

First, the working function:

function lookUpProfile(name, prop){
    for(var i = 0; i < contacts.length; i++){
        if(name === contacts[i]["firstName"]){
            if(contacts[i].hasOwnProperty(prop)){
                return contacts[i][prop];
            }
            return "No such property";
        }
    }
    return "No such contact";
}

The non working forEach function:

function lookUpProfile(name, prop){
    contacts.forEach(function(contact){
        if(name === contact["firstName"]){
            if(contact.hasOwnProperty(prop)){
                return contact[prop];
            }
            return "No such property";
        }
    });
    return "No such contact";
}

The array that is being looped through:

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"]
}

];

The problem guidelines:

We have an array of objects representing different people in our contacts lists.
A lookUpProfile function that takes name and a property (prop) as arguments has been pre-written for you.
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 "No such
contact".
If prop does not correspond to any valid properties of a contact
found to match name then return "No such property".

You can't, and you shouldn't, use `forEach`. If you're looking for a better looping syntax, go `for … of`. — Bergi, Jan 23 '20 at 21:14
When you `return` from a `for()` loop you return from the parent. When you return from a callback function like the one you pass to `forEach`, you return from that callback. — coreyward, Jan 23 '20 at 21:15
Welcome to Stack Overflow. You can just use `.filter()` or a `.reduce()`, where you can return a value — Mikkel, Jan 23 '20 at 21:15
@user1538301 I still [recommend avoiding `forEach`](https://stackoverflow.com/a/49420944/1048572) in general, which helps avoiding problems like this here. — Bergi, Jan 23 '20 at 21:20
@Bergi that answer is 25% subjective (readability) and 25% arbitary (the const case), I will give you that a `for` loop is typically more performant (no closure) and you can use control statements. The only time I ever use `for` is when I absolutely need to interrupt the loop at some point. I still think to say that one "can't" and "shouldn't" use `forEach` is a bit extreme — gabriel.hayes, Jan 23 '20 at 21:30
The answer is use `find()` not forEach since forEach is designed to loop over everything. Other methods like every() and some() are also overlooked when people want to short circuit for each. — epascarello, Jan 23 '20 at 21:37
@user1538301 The "can't" was specific to what the OP was trying to do here, where he needs control flow statements. — Bergi, Jan 23 '20 at 21:41

How can I write this function with a forEach loop?

0 Answers0