Is a closure variable not created if not used? [duplicate]
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Why does Chrome debugger think closed local variable is undefined?
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In this example, Google Chrome Devtools won't find variable "y" in closure scope, but it will show "x".
My guess is that "y" won't appear because it's not used.
Am I right?
javascript closures
google-chrome-devtools asked 23 hours ago
Guillaume Renoult
718616
marked as duplicate by Bergi javascript
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6 hours ago
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This question already has an answer here:
Why does Chrome debugger think closed local variable is undefined?
5 answers
In this example, Google Chrome Devtools won't find variable "y" in closure scope, but it will show "x".
My guess is that "y" won't appear because it's not used.
Am I right?
javascript closures
google-chrome-devtools asked 23 hours ago
Guillaume Renoult
718616
marked as duplicate by Bergi javascript
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6 hours ago
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
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I'd think the variable is created, but afterouterruns, it can't be referenced anymore, so it gets GC'd, though maybe smart compilers would see thatyis never used and not bother assigning it. Might be engine-dependent.
– CertainPerformance
23 hours ago
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up vote
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down vote
favorite
This question already has an answer here:
Why does Chrome debugger think closed local variable is undefined?
5 answers
In this example, Google Chrome Devtools won't find variable "y" in closure scope, but it will show "x".
My guess is that "y" won't appear because it's not used.
Am I right?
javascript closures
google-chrome-devtools asked 23 hours ago
Guillaume Renoult
718616
This question already has an answer here:
Why does Chrome debugger think closed local variable is undefined?
5 answers
In this example, Google Chrome Devtools won't find variable "y" in closure scope, but it will show "x".
My guess is that "y" won't appear because it's not used.
Am I right?
This question already has an answer here:
Why does Chrome debugger think closed local variable is undefined?
5 answers
javascript closures
google-chrome-devtools javascript closures
google-chrome-devtools asked 23 hours ago
Guillaume Renoult
718616
asked 23 hours ago
Guillaume Renoult
718616
asked 23 hours ago
Guillaume Renoult
718616
asked 23 hours ago
Guillaume Renoult
718616
asked 23 hours ago
Guillaume Renoult
718616
718616
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6 hours ago
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6 hours ago
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
1
I'd think the variable is created, but afterouterruns, it can't be referenced anymore, so it gets GC'd, though maybe smart compilers would see thatyis never used and not bother assigning it. Might be engine-dependent.
– CertainPerformance
23 hours ago
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1
I'd think the variable is created, but afterouterruns, it can't be referenced anymore, so it gets GC'd, though maybe smart compilers would see thatyis never used and not bother assigning it. Might be engine-dependent.
– CertainPerformance
23 hours ago
1
1
I'd think the variable is created, but after
outer runs, it can't be referenced anymore, so it gets GC'd, though maybe smart compilers would see that y is never used and not bother assigning it. Might be engine-dependent.– CertainPerformance
23 hours ago
I'd think the variable is created, but after
outer runs, it can't be referenced anymore, so it gets GC'd, though maybe smart compilers would see that y is never used and not bother assigning it. Might be engine-dependent.– CertainPerformance
23 hours ago
add a comment |
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It looks like it's engine dependent.
On Google Chrome (Version 70.0.3538.77 (Official Build) (64-bit)), I can't see "y" variable:
However on Firefox variable "y" is accessible:
I'm not sure how these engines work, I assume Chrome during compile time have a look at variable "y" and says "hey it's not used in this scope, we don't need it". Whereas Firefox includes it.
answered 6 hours ago
Guillaume Renoult
718616
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1 Answer
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1 Answer
1
active
oldest
votes
active
oldest
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active
oldest
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up vote
0
down vote
It looks like it's engine dependent.
On Google Chrome (Version 70.0.3538.77 (Official Build) (64-bit)), I can't see "y" variable:
However on Firefox variable "y" is accessible:
I'm not sure how these engines work, I assume Chrome during compile time have a look at variable "y" and says "hey it's not used in this scope, we don't need it". Whereas Firefox includes it.
answered 6 hours ago
Guillaume Renoult
718616
add a comment |
up vote
0
down vote
It looks like it's engine dependent.
On Google Chrome (Version 70.0.3538.77 (Official Build) (64-bit)), I can't see "y" variable:
However on Firefox variable "y" is accessible:
I'm not sure how these engines work, I assume Chrome during compile time have a look at variable "y" and says "hey it's not used in this scope, we don't need it". Whereas Firefox includes it.
answered 6 hours ago
Guillaume Renoult
718616
add a comment |
up vote
0
down vote
up vote
0
down vote
It looks like it's engine dependent.
On Google Chrome (Version 70.0.3538.77 (Official Build) (64-bit)), I can't see "y" variable:
However on Firefox variable "y" is accessible:
I'm not sure how these engines work, I assume Chrome during compile time have a look at variable "y" and says "hey it's not used in this scope, we don't need it". Whereas Firefox includes it.
answered 6 hours ago
Guillaume Renoult
718616
It looks like it's engine dependent.
On Google Chrome (Version 70.0.3538.77 (Official Build) (64-bit)), I can't see "y" variable:
However on Firefox variable "y" is accessible:
I'm not sure how these engines work, I assume Chrome during compile time have a look at variable "y" and says "hey it's not used in this scope, we don't need it". Whereas Firefox includes it.
answered 6 hours ago
Guillaume Renoult
718616
answered 6 hours ago
Guillaume Renoult
718616
answered 6 hours ago
Guillaume Renoult
718616
answered 6 hours ago
Guillaume Renoult
718616
718616
add a comment |
add a comment |
1
I'd think the variable is created, but after
outerruns, it can't be referenced anymore, so it gets GC'd, though maybe smart compilers would see thatyis never used and not bother assigning it. Might be engine-dependent.– CertainPerformance
23 hours ago