Lexical closures are functions, often anonymous, that capture, or close over, their lexical environment. Lexical closures are used extensively in functional programming techniques that involve higher-order functions.
Questions tagged [lexical-closures]
53 questions
0
votes
2 answers
Dart. Where argument of anonymous function came from?
In example below there (num i) stuff, where it get it's value when makeAddr() called ?
Function makeAdder(num addBy) {
return (num i) => addBy + i;
}
void main() {
// Create a function that adds 2.
var add2 = makeAdder(2);
// Create a…
Jack J
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0
votes
3 answers
How does the Javascript closure with function works?
Hi i have been exploring closures and javascript core concepts i couldn't understand why does the console.log(factory[i]) outputs undefined i have pushed my function inside there right? And if i call temp outside the loop it says undefined whereas…
Kannan T
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0
votes
0 answers
lexical scoping example not working
Why would this closure not work?
var derivedKey;
lightwallet.keystore.deriveKeyFromPassword(password, function (err, pwDerivedKey) {
derivedKey = pwDerivedKey;
});
if (!derivedKey){
console.error ("ERROR no derivedKey");
}
Thows…
Roland Kofler
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0
votes
3 answers
Javascript Lexical scope
I am trying to understand the concept of Lexical scope. As far as i know Lexical scope does not work backwards. In the below javascript code i have declared variable 'name' in scope3() function. But i tried to call it in scope1() and scope2()…
SsNewbie
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0
votes
3 answers
Does using lambda functions to simulate lexical clousures have unforseen performace / implementation issues?
Program 1:
#include
std::string Hello(void){return "Hello";}
std::string World(void){return "world!";}
int main(){
std::cout << Hello() << " " << World() << std::endl;
}
The functions Hello() and World() exist in the global…
Trevor Hickey
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-1
votes
3 answers
Is it possible to differentiate between a non-capturing function and a closure in Javascript?
The two function objects:
// toplevel
var f1 = function(){return k;};
var f2 = (function(k){return function(){return k;}})(42);
have the same source code "function(){return k;}" but f1 is a function where k is looked up in the global environment,…
6502
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-2
votes
2 answers
Difference between closures and normal functions
I was going through the closures definition in Mozilla and found this example -
function makeSizer(size) {
return function () {
document.body.style.fontSize = `${size}px`;
};
}
const size12 = makeSizer(12);
const size14 =…
beta programmers
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-2
votes
1 answer
Code with var variable at each level gives unexpected result
Please provide an explanation why the output will be 4. I am trying to understand that the output is 4 but cannot find the reason why is it not 3.
var x=4,
obj={
x: 3,
bar:function(){
var x = 2;
setTimeout(function(){
…
Satyam Kumar
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