C#•13mo ago

❔ ✅ Mind explaining a code to me?

public static int? Closest(int[] arr)
  {
    var min = arr.Distinct().Where(x => Math.Abs(x) == arr.Min(Math.Abs));
    return min.Count() == 1 ? min.First() : (int?) null;
  }

public static int? Closest(int[] arr)
  {
    var min = arr.Distinct().Where(x => Math.Abs(x) == arr.Min(Math.Abs));
    return min.Count() == 1 ? min.First() : (int?) null;
  }

67 Replies

Angius•13mo ago

It's a bunch of LINQ code .Distinct() gets only unique elements .Where() filters the collection by the predicate .Count() gets the amount of items in the collection .First() gets the first element condition ? iftrue : iffalse is a ternary expression

AhmedOP•13mo ago

removes duplicates

Angius•13mo ago

x => stuff is a lambda

AhmedOP•13mo ago

i don't get this meaning? but idk what it means in this context

MODiX•13mo ago

Angius

REPL Result: Success

new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}.Where(number => number % 2 == 0)

new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}.Where(number => number % 2 == 0)

Result: WhereArrayIterator<int>

[
  2,
  4,
  6,
  8,
  10
]

[
  2,
  4,
  6,
  8,
  10
]

Compile: 574.081ms | Execution: 98.215ms | React with ❌ to remove this embed.

AhmedOP•13mo ago

filters with a condition i thought => was to return a value

MODiX•13mo ago

Angius

REPL Result: Success

int[] numbers = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
foreach(int number in numbers)
{
    string message = number % 2 == 0 ? "even" : "odd";
    Console.WriteLine($"Number {number} is {message}");
}

int[] numbers = new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
foreach(int number in numbers)
{
    string message = number % 2 == 0 ? "even" : "odd";
    Console.WriteLine($"Number {number} is {message}");
}

Console Output

Number 1 is odd
Number 2 is even
Number 3 is odd
Number 4 is even
Number 5 is odd
Number 6 is even
Number 7 is odd
Number 8 is even
Number 9 is odd
Number 10 is even

Number 1 is odd
Number 2 is even
Number 3 is odd
Number 4 is even
Number 5 is odd
Number 6 is even
Number 7 is odd
Number 8 is even
Number 9 is odd
Number 10 is even

Compile: 782.019ms | Execution: 141.873ms | React with ❌ to remove this embed.

Angius•13mo ago

Kinda-sorta The lambda number => number % 2 == 0 will return a boolean If that boolean is false, the element gets filtered out

AhmedOP•13mo ago

AhmedOP•13mo ago

is number a made up var? number => number... that one

Angius•13mo ago

number => number % 2 == 0;

number => number % 2 == 0;

is basically a shorter, anonymous version of

public bool DoSuff(int number)
{
    return number % 2 == 0;
}

public bool DoSuff(int number)
{
    return number % 2 == 0;
}

It's a parameter

AhmedOP•13mo ago

is it only for lists? like

Angius•13mo ago

No, you can use a lambda whenever, wherever

AhmedOP•13mo ago

for (x in var_name){}

for (x in var_name){}

the

but in this context is it for lists

MODiX•13mo ago

Angius

REPL Result: Success

var sum = (int a, int b) => a + b;

sum(2, 4)

var sum = (int a, int b) => a + b;

sum(2, 4)

Result: int

Compile: 596.015ms | Execution: 63.795ms | React with ❌ to remove this embed.

AhmedOP•13mo ago

=> is for returning

Angius•13mo ago

If you're talking about LINQ, the .Where() part, then it's for any IEnumerable Including lists It just happens to take a Func<T, bool> as a parameter

AhmedOP•13mo ago

so public static int? Closest(int[] arr) { var min = arr.Distinct().Where(x => Math.Abs(x) == arr.Min(Math.Abs)); return min.Count() == 1 ? min.First() : (int?) null; } that's saying Distinct removes all dupes math.abs(x) == arr.Min(Math.Abs)) the absolute value of x is equal to the minimum absolute value in the list?

Angius•13mo ago

Yep

AhmedOP•13mo ago

so like

Angius•13mo ago

.Where() removes all elements where that is not true

AhmedOP•13mo ago

yeah so it filters to the condition new int[]{1, 2, 3, 4, 5, 6, 7, 8, 9, 10} in this list min abs value is 1 and the value of x is in the first iteration 1 yeah bro i'm so lost with the logic too like i was confused with

for (int x = 0; x < 100; x++){}

for (int x = 0; x < 100; x++){}

but i learned the first section is when you define x, next is the condition, and next is what happens when the condition is met without Distinct() would it still filter?

Angius•13mo ago

Yeah

AhmedOP•13mo ago

or do you need Distinct() and Where() together so distinct removes dupes and where filters after dupes have been removed?

Angius•13mo ago

Exactly

AhmedOP•13mo ago

shoot

Angius•13mo ago

You can chain LINQ methods almost at will

AhmedOP•13mo ago

i'm basically new beginner i'm sixth form y12 next yr we gonna make websites so i gotta study c# a lot

Angius•13mo ago

Well, lambdas and LINQ are definitely not beginner topics

AhmedOP•13mo ago

i have known lambda from time basics of it so to find the number closest to 0 find the smallest possible value in abs form that's literally it

softmek•13mo ago

AhmedOP•13mo ago

what's the point of all that when you're tryna find the number closest to 0

AhmedOP•13mo ago

softmek•13mo ago

Am just explaining your answer, You never sent your qn

AhmedOP•13mo ago

no i wasn't tryna be rude

softmek•13mo ago

no worries, send the question

AhmedOP•13mo ago

what's min.Count() and min.First()

MODiX•13mo ago

akhahmed

Quoted by

<@1153068032533483588> from #Mind explaining a code to me? (click here)

React with ❌ to remove this embed.

MODiX•13mo ago

Angius

REPL Result: Success

new int[]{1, 2, 3, 4, 5, 6}.Count()

new int[]{1, 2, 3, 4, 5, 6}.Count()

Result: int

Compile: 542.876ms | Execution: 51.420ms | React with ❌ to remove this embed.

AhmedOP•13mo ago

Simply find the closest value to zero from the list. Notice that there are negatives in the list. List is always not empty and contains only integers. Return None if it is not possible to define only one of such values. And of course, we are expecting 0 as closest value to zero.

MODiX•13mo ago

Angius

REPL Result: Success

new int[]{1, 2, 3, 4, 5, 6}.First()

new int[]{1, 2, 3, 4, 5, 6}.First()

Result: int

Compile: 541.726ms | Execution: 67.039ms | React with ❌ to remove this embed.

AhmedOP•13mo ago

Angius•13mo ago

I highly recommend trying to run the code and observing the results lol Learning by doing and all that jazz

AhmedOP•13mo ago

why is he doing min.Count ==1 i know i receive so many

Angius•13mo ago

Checking if the collection has only a single element

AhmedOP•13mo ago

errors cause they put it in a clas s

Angius•13mo ago

If it does, then that element is the closest to zero If there's more, that means there are more elements just as close to zero

softmek•13mo ago

sending my solution in a sec, i'll create a function and explain in comments public static int? Closest(int[] arr) { int closestAbsoluteValue = arr.Select(Math.Abs).Min(); // Find the minimum absolute value var closestValues = arr.Where(x => Math.Abs(x) == closestAbsoluteValue); // Find values with the closest absolute value if (closestValues.Count() == 1) { return closestValues.First(); // If only one closest value found, return it } else { return null; // If multiple values with the same absolute value exist, return None } }

Angius•13mo ago

$code

MODiX•13mo ago

To post C# code type the following: ```cs // code here ``` Get an example by typing $codegif in chat For longer snippets, use: https://paste.mod.gg/

AhmedOP•13mo ago

$code

public static int? Closest(int[] arr)
{
    int closestAbsoluteValue = arr.Select(Math.Abs).Min(); // Find the minimum absolute value

    var closestValues = arr.Where(x => Math.Abs(x) == closestAbsoluteValue); // Find values with the closest absolute value

    if (closestValues.Count() == 1)
    {
        return closestValues.First(); // If only one closest value found, return it
    }
    else
    {
        return null; // If multiple values with the same absolute value exist, return None
    }
}

public static int? Closest(int[] arr)
{
    int closestAbsoluteValue = arr.Select(Math.Abs).Min(); // Find the minimum absolute value

    var closestValues = arr.Where(x => Math.Abs(x) == closestAbsoluteValue); // Find values with the closest absolute value

    if (closestValues.Count() == 1)
    {
        return closestValues.First(); // If only one closest value found, return it
    }
    else
    {
        return null; // If multiple values with the same absolute value exist, return None
    }
}

MODiX•13mo ago

To post C# code type the following: ```cs // code here ``` Get an example by typing $codegif in chat For longer snippets, use: https://paste.mod.gg/

AhmedOP•13mo ago

public static int? Closest(int[] arr)
{
    int closestAbsoluteValue = arr.Select(Math.Abs).Min(); // Find the minimum absolute value

    var closestValues = arr.Where(x => Math.Abs(x) == closestAbsoluteValue); // Find values with the closest absolute value

    if (closestValues.Count() == 1)
    {
        return closestValues.First(); // If only one closest value found, return it
    }
    else
    {
        return null; // If multiple values with the same absolute value exist, return None
    }
}

public static int? Closest(int[] arr)
{
    int closestAbsoluteValue = arr.Select(Math.Abs).Min(); // Find the minimum absolute value

    var closestValues = arr.Where(x => Math.Abs(x) == closestAbsoluteValue); // Find values with the closest absolute value

    if (closestValues.Count() == 1)
    {
        return closestValues.First(); // If only one closest value found, return it
    }
    else
    {
        return null; // If multiple values with the same absolute value exist, return None
    }
}

$code

MODiX•13mo ago

To post C# code type the following: ```cs // code here ``` Get an example by typing $codegif in chat For longer snippets, use: https://paste.mod.gg/

softmek•13mo ago

look, good

AhmedOP•13mo ago

i copied yours 💀 ofc i'm not gonna use it tho

softmek•13mo ago

AhmedOP•13mo ago

    var closestValues = arr.Where(x => Math.Abs(x) == closestAbsoluteValue); // Find values with the closest absolute value

    var closestValues = arr.Where(x => Math.Abs(x) == closestAbsoluteValue); // Find values with the closest absolute value

last thing i wanna know why is he tryna find the values with the closest abs value

softmek•13mo ago

Angius•13mo ago

Because -2 is as close to zero as +2

AhmedOP•13mo ago

oh wait wait

Angius•13mo ago

So you need to treat negative and positive values the same, in terms of proximity to 0

softmek•13mo ago

So, by finding the values with the closest absolute value to zero, the function determines which number or numbers are closest to zero, considering both positive and negative numbers equally in their proximity to zero. If there's a unique value that's closest to zero, the function returns that value. If multiple values share the same closest absolute distance to zero, it indicates that there's no singular closest value to zero, so the function returns None.

AhmedOP•13mo ago

shoot shoot shoot public static int? Closest(int[] arr) { var min = arr.Distinct().Where(x => Math.Abs(x) == arr.Min(Math.Abs)); return min.Count() == 1 ? min.First() : (int?) null; } Distince() removes all dupes, Where()... sorts it out so only the smallest value is left, there would be 2 values left if there was a negative variant. IF there is either positive or negative, it will min.First(), and if there are 2 values with equal prox ( e.g. -2, 2 ) then it returns null?

    return min.Count() == 1 ? min.First() : (int?) null;

    return min.Count() == 1 ? min.First() : (int?) null;

why can't it be

    return min.Count() == 1 ? min.First() : null;

    return min.Count() == 1 ? min.First() : null;

Math.Abs holds all unique integers, and when == is set, it makes the list smaller because basically a condition has been set where it's equal to the min abs value perfect, thank you so much :))) !close

Accord•13mo ago

Closed!

softmek•13mo ago

(int?) means it's a nullable integer value, null return emply. which means (int?) will not work for non-numerical values,

Accord•13mo ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ ✅ Mind explaining a code to me?