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Questions tagged [let]

In Lisp-like and functional languages, introduces a list of local variables, each (possibly optionally) with its initial value.

In Lisp-like and functional languages, introduces a list of local variables, each (possibly optionally) with its initial value. It is illegal to refer to any of the new variables while calculating their initial values ( lets you do that), though in Haskell it is legal (its let is actually letrec).

LET is a special form in Common Lisp, Scheme, Clojure and other Lisp dialects which introduces a list of local variables as pairs of name-value bindings, for use within its body. For instance, in this expression:

(let ((variable1 (+ 1 1)))
  variable1)

variable1 gets bound to the 2 value, and the whole expression returns 2 as a result.

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what is happening inside the loop and how the output is like this for let variable?

let printNumTwo; for (let i = 0; i < 3; i++) { if (i === 2) { printNumTwo = function() { return i; }; } } console.log(printNumTwo()); output : 2 How is this output become 2; explain what is happening inside the loop and scope…
V V ARJUN
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JavaScript Global Variable Not Changing

I'm new to JavaScript and I made a simple stopwatch constructor: function Stopwatch() { var started = false; var elapsed; var start; d = new Date(); this.duration = function() { if (started) { throw…
Wilhelmo Gutred
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As standard, does Scheme have any syntactic sugar for trivial calls to let?

I find that let has too many brackets. For example, when writing the following block of code, it was very easy to misplace lets many closing brakcets. (define (adder n) (let ((a 1)) (+ a n))) All of these brackets are clearly necessary…
J. Mini
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Let bindings to one function

So, I can't figure out how you make 2 let bindings to the same function result (tuple) in FSharp. For example, if I have a function: Play() whose output is (x,y). And i wanna use x and y in another function. Right now I write: Let first = fst…
AlphaList
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How to add a number from a local txt file into JS "let" keyword

I am trying to place a number from a local TXT file in the "let count = 0" instruction, so "let count = number.txt" That way the counter will read the number placed on the txt file and perform the addition/subtraction operation. Thank…
Y M
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How do I get the console to output my number?

I'm just a beginner in JavaScript and I can't solve a problem with a function. I need the code to cycle through an array of let's say the numbers ["3", "5", "7", "4", "9"] and console.log only the highest number in the array. This is the code I'm…
Kas
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why use let replace var in recursion is better?

when i try to do a LeetCode question # 25, use var can't pass, but use let can pass var /** * Definition for singly-linked list. * function ListNode(val) { * this.val = val; * this.next = null; * } */ /** * @param {ListNode} head *…
siyao dai
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How does props and state work in REACTjs?

Im new to reactjs. I dont really understand how does props and state work. From my research i have found that props are passed from parent to child. And states can only be used in a single component. But when i see these codes below, i have no idea…
Sharana Dharshikgan
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How do I get the end result of my let product to multiply 100

Directions: In the product object that is provided, the cost and deliveryFee are in US dollars. Add a method named newPayments to the product object that sums the cost and deliveryFee and returns the result in cents (multiply by 100). Remember to…
Ern
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Html template assignment in Angular

Lets say I have the below HTML Template whats the best way to assign it to a variable in Angular Project public template = '

This is a p tag

' How do I make such kind of assignment in typescript?
Jay
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What's the difference between var and let?

The MDN tutorial for JavaScript says Back when JavaScript was first created, there was only var. This works basically fine in most cases, but it has some issues in the way it works — its design can sometimes be confusing or downright…
Sebastian
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How to get let inside a block when adding iterations to it?

Imagine: const arr = ['a','b','c']; let num; const incr = arr.map((el, i) => { num += el; } // num is undefined in incr How to get num inside incr function so it can increment itself on each loop? Trying to put num inside incr will not result in…
Dom
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Why declare anonymous function and then assign to variable?

Can someone explain why we create a function and then use 'let' to assign the anonymous function to a variable? What's the point of writing it like that? function buildName(firstName: string, ...restOfName: string[]) { return firstName + " " +…
JenniferDevelopez
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JQuery - syntax

I have created the variable $divquallist like this... let $divquallist = $("div.quallist"); but I can't figure our how to access the css property of all trs of the variable. When I reference the element with jQuery , I can do…
Dave Davis
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Swift give let values

I want to write dont let values I have "id": 17, "name": "", "team_id": 4, "is_delete": false, "created_at": "2018-04-30", "members": [ { "id": 42, "username": "ie", } ], …
Nazar
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