NW-6 | Fikret Ellek | JS3| [TECH ED] Array Destructuring | WEEK-3 #311
Conversation
|
| function isGryffindor(list) { | ||
| list.map(({ firstName, lastName, house }) => { | ||
| if (house === "Gryffindor") console.log(firstName, lastName, house); | ||
| }); | ||
| } | ||
| function havePet(list) { | ||
| list.map(({ firstName, lastName, pet, occupation }) => { | ||
| if (pet && occupation === "Teacher") console.log(firstName, lastName, pet); | ||
| }); | ||
| } |
There was a problem hiding this comment.
Good attempt!
It looks like you are almost there, but be careful when reading requirements, you did not need to log the house in either task, also the first and last name needed to be separated by a space. This code will print HarryPotterGryffindor rather than Harry Potter.
Other improvements:
I would argue however that Array.map() is not the most appropriate method for this task.
Array.map() creates a new instance of an array and returns a value on every iteration, and in this case, you are not assigning the value of this new array to a variable, secondly, you are not returning anything inside the callback function (the function passed into Array.map()).
This means if you assigned the new array to a variable it would just be an array with X number of null values.
In my opinion, there are two improved ways to do this:
First (cleanest):
list
.filter( person => person.house === "Gryffindor" )
.forEach( person => console.log(`${person.firstName} ${person.lastName}`) );
Article on Array.filter() method
Second:
list.forEach( person => {
if ( person.house === "Gryffindor" )
{
console.log(`${person.firstName} ${person.lastName}`)
}
} );
There was a problem hiding this comment.
Thank you very much Jack, using methods one after another is really simple and effective usage. I didn't think about it before.
I see the difference between map and forEach better now. I always mixed those two.
| function printBill(list) { | ||
| let total = 0; | ||
| console.log("QTY", "\t", "ITEM", "\t\t", "TOTAL"); | ||
| list.map(({ quantity, itemName, unitPrice }) => { | ||
| console.log(quantity, "\t", itemName, "\t", unitPrice * quantity); | ||
| total += quantity * unitPrice; | ||
| }); | ||
| console.log("Total:", total); | ||
| } | ||
|
|
||
| printBill(order); |
There was a problem hiding this comment.
Good job!
Also, an improvement you could make to this solution would be to use Array.reduce() to create a running aggregate instead of defining totalPrice outside of the loop.
Here is a link that explains using reduce to calculate a sum.
https://linuxhint.com/call-reduce-on-an-array-of-objects-to-sum-their-properties/
There was a problem hiding this comment.
that's a really useful method. I wish I knew the importance of code review and learn from it long before. Thank you very much for your brilliant and constructive feedback. Sorry for replying after a month. I never knew learning from code review would be this effective. 🙏
Learners, PR Template
Self checklist
Changelist
Briefly explain your PR.
Questions
Ask any questions you have for your reviewer.