Javascript - scoping an incrementing-loop counter only to that loop
-3
I've run into this error multiple times now, and wondering if there's a way to have the code auto control for it?
var length = some_array.length
for (var i = 0; i < length; i ++) {
someMethod(some_array[i].name)
}
function someMethod(name) {
var length = other_array.length
for (var i = 0; i < length; i ++ ) {
// some code
}
}
The code above doesn't run properly because the inner i and length carry over to the outer level code. So to actually make it work, I have to manually set different variables to manage the scoping. I.e., something like the below works:
var length = some_array.length
for (var i = 0; i < length; i ++) {
someMethod(some_array[i].name)
}
function someMethod(name) {
var s_length = other_array.s_length
for (var s_i = 0; s_i < length; s_i ++ ) {
// some code
}
}
But of course, it's hard to always remember when an inner function has another loop in it. Wondering if there's a way to control it so that loop variables are always only constrained to THAT loop itself.
javascript
edited Nov 26 '18 at 2:21
ggorlen
7,6483926
asked Nov 26 '18 at 2:19
jamesjames
1,72732859
add a comment |
-3
I've run into this error multiple times now, and wondering if there's a way to have the code auto control for it?
var length = some_array.length
for (var i = 0; i < length; i ++) {
someMethod(some_array[i].name)
}
function someMethod(name) {
var length = other_array.length
for (var i = 0; i < length; i ++ ) {
// some code
}
}
The code above doesn't run properly because the inner i and length carry over to the outer level code. So to actually make it work, I have to manually set different variables to manage the scoping. I.e., something like the below works:
var length = some_array.length
for (var i = 0; i < length; i ++) {
someMethod(some_array[i].name)
}
function someMethod(name) {
var s_length = other_array.s_length
for (var s_i = 0; s_i < length; s_i ++ ) {
// some code
}
}
But of course, it's hard to always remember when an inner function has another loop in it. Wondering if there's a way to control it so that loop variables are always only constrained to THAT loop itself.
javascript
edited Nov 26 '18 at 2:21
ggorlen
7,6483926
asked Nov 26 '18 at 2:19
jamesjames
1,72732859
3
Take a look at theletkeyword.
– ggorlen
Nov 26 '18 at 2:21
2
The code above doesn't run properly because the inner i and length carry over to the outer levelno, they don't - you must be doing something else wrong
– Jaromanda X
Nov 26 '18 at 2:40
add a comment |
-3
-3
-3
I've run into this error multiple times now, and wondering if there's a way to have the code auto control for it?
var length = some_array.length
for (var i = 0; i < length; i ++) {
someMethod(some_array[i].name)
}
function someMethod(name) {
var length = other_array.length
for (var i = 0; i < length; i ++ ) {
// some code
}
}
The code above doesn't run properly because the inner i and length carry over to the outer level code. So to actually make it work, I have to manually set different variables to manage the scoping. I.e., something like the below works:
var length = some_array.length
for (var i = 0; i < length; i ++) {
someMethod(some_array[i].name)
}
function someMethod(name) {
var s_length = other_array.s_length
for (var s_i = 0; s_i < length; s_i ++ ) {
// some code
}
}
But of course, it's hard to always remember when an inner function has another loop in it. Wondering if there's a way to control it so that loop variables are always only constrained to THAT loop itself.
javascript
edited Nov 26 '18 at 2:21
ggorlen
7,6483926
asked Nov 26 '18 at 2:19
jamesjames
1,72732859
I've run into this error multiple times now, and wondering if there's a way to have the code auto control for it?
var length = some_array.length
for (var i = 0; i < length; i ++) {
someMethod(some_array[i].name)
}
function someMethod(name) {
var length = other_array.length
for (var i = 0; i < length; i ++ ) {
// some code
}
}
The code above doesn't run properly because the inner i and length carry over to the outer level code. So to actually make it work, I have to manually set different variables to manage the scoping. I.e., something like the below works:
var length = some_array.length
for (var i = 0; i < length; i ++) {
someMethod(some_array[i].name)
}
function someMethod(name) {
var s_length = other_array.s_length
for (var s_i = 0; s_i < length; s_i ++ ) {
// some code
}
}
But of course, it's hard to always remember when an inner function has another loop in it. Wondering if there's a way to control it so that loop variables are always only constrained to THAT loop itself.
javascript
javascript
edited Nov 26 '18 at 2:21
ggorlen
7,6483926
asked Nov 26 '18 at 2:19
jamesjames
1,72732859
edited Nov 26 '18 at 2:21
ggorlen
7,6483926
asked Nov 26 '18 at 2:19
jamesjames
1,72732859
edited Nov 26 '18 at 2:21
ggorlen
7,6483926
edited Nov 26 '18 at 2:21
ggorlen
7,6483926
edited Nov 26 '18 at 2:21
ggorlen
7,6483926
7,6483926
asked Nov 26 '18 at 2:19
jamesjames
1,72732859
asked Nov 26 '18 at 2:19
jamesjames
1,72732859
asked Nov 26 '18 at 2:19
jamesjames
1,72732859
1,72732859
3
Take a look at theletkeyword.
– ggorlen
Nov 26 '18 at 2:21
2
The code above doesn't run properly because the inner i and length carry over to the outer levelno, they don't - you must be doing something else wrong
– Jaromanda X
Nov 26 '18 at 2:40
add a comment |
3
Take a look at theletkeyword.
– ggorlen
Nov 26 '18 at 2:21
2
The code above doesn't run properly because the inner i and length carry over to the outer levelno, they don't - you must be doing something else wrong
– Jaromanda X
Nov 26 '18 at 2:40
3
3
Take a look at the
let keyword.– ggorlen
Nov 26 '18 at 2:21
Take a look at the
let keyword.– ggorlen
Nov 26 '18 at 2:21
2
2
The code above doesn't run properly because the inner i and length carry over to the outer level no, they don't - you must be doing something else wrong– Jaromanda X
Nov 26 '18 at 2:40
The code above doesn't run properly because the inner i and length carry over to the outer level no, they don't - you must be doing something else wrong– Jaromanda X
Nov 26 '18 at 2:40
add a comment |
2 Answers
2
active
oldest
votes
0
This is why let keyword is a better option than var- it keeps the scope to just the function or method that calls it.
The following snippet consoles -
0 / test 1 / 0 / test a
0 / test 1 / 1 / test b
1 / test 2 / 0 / test a
1 / test 2 / 1 / test b
ie: for each item of some_array - it calls someMethod and consoles the name of the first array as well as each iteration of the second array (other_array).
let some_array=[{id: '1', name: 'test 1'},{id: '2', name: 'test 2'}];
let other_array=[{id: 'a', name: 'test a'},{id: 'b', name: 'test b'}];
let length = some_array.length;
for (let i = 0; i < length; i ++) {
someMethod(i, some_array[i].name)
}
function someMethod(index, name) {
let length = other_array.length
for (let i = 0; i < length; i ++ ) {
console.log(index + ' / ' + name + ' / ' + i + ' / ' + other_array[i].name);
}
}answered Nov 26 '18 at 2:24
gavgrifgavgrif
8,6912918
1
I get the same output regardless ofletorvarhere. Maybe there's a better example?iinsidesomeMethodis scoped to the function.
– Mark Meyer
Nov 26 '18 at 2:32
Each i IS scoped to its location - I just amended it to log the i's as well and as you can see - each log shows its place in the sequence - 0/0 , 0,1 , 1,0 ,11 - or in other words - for each of the i's in the first gtopu its calling the method and in the method - its iteratnig over the second list.
– gavgrif
Nov 26 '18 at 2:40
So, maybe I'm just missing the point. What would be different if you replaced all thelets withvars?
– Mark Meyer
Nov 26 '18 at 2:48
add a comment |
0
SCOPE
In JavaScript there are two types of scope:
Local scope
Global scope
JavaScript has function scope: Each function creates a new scope.
let allows you to declare variables that are limited in scope to the block.
Notice how var create a property on the global object but let is undefined.
var x = 'global';
let y = 'global';
console.log(this.x); // "global"
console.log(this.y); // undefined
Let's try it with your code.
let some_array = [{ name: 'Angel' }, { name: 'James' }]
let other_array = ['0','1'];
//let i is declared local
for (let i = 0; i < some_array.length; i++) {
someMethod(some_array[i].name) //"let" some_array variable is required here to the local "for loop" scope.
}
function someMethod(name) {
//let i is declared local here again so it's considered a new variable i.
for (let i = 0; i < some_array.length; i++) {
console.log(name)
}
}
For more examples about scope in Javascript
answered Nov 26 '18 at 2:42
Angel RomaAngel Roma
19829
Wouldn'tvar ialso be local tosomeMethod()?
– Mark Meyer
Nov 26 '18 at 2:50
@MarkMeyerletgives you the privilege to declare variables that are limited in scope to the block, statement of expression unlikevar.varis rather a keyword which defines a variable globally regardless of block scope
– Angel Roma
Nov 26 '18 at 2:55
That's not quite correct. Inside a functionvaris scoped to that function.
– Mark Meyer
Nov 26 '18 at 3:01
varkeyword defines a variable globally regardless of block scope.
– Angel Roma
Nov 26 '18 at 3:06
But it doesn't define it globally when used inside a function. In the example you have, it makes no difference whether you useletorvarforibecause the second one is defined inside the functionsomeMethod. It will be a distinct variable unrelated to theioutside the function. Nothing changes if you usevarinstead ofletin your example.
– Mark Meyer
Nov 26 '18 at 3:11
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
0
This is why let keyword is a better option than var- it keeps the scope to just the function or method that calls it.
The following snippet consoles -
0 / test 1 / 0 / test a
0 / test 1 / 1 / test b
1 / test 2 / 0 / test a
1 / test 2 / 1 / test b
ie: for each item of some_array - it calls someMethod and consoles the name of the first array as well as each iteration of the second array (other_array).
let some_array=[{id: '1', name: 'test 1'},{id: '2', name: 'test 2'}];
let other_array=[{id: 'a', name: 'test a'},{id: 'b', name: 'test b'}];
let length = some_array.length;
for (let i = 0; i < length; i ++) {
someMethod(i, some_array[i].name)
}
function someMethod(index, name) {
let length = other_array.length
for (let i = 0; i < length; i ++ ) {
console.log(index + ' / ' + name + ' / ' + i + ' / ' + other_array[i].name);
}
}answered Nov 26 '18 at 2:24
gavgrifgavgrif
8,6912918
1
I get the same output regardless ofletorvarhere. Maybe there's a better example?iinsidesomeMethodis scoped to the function.
– Mark Meyer
Nov 26 '18 at 2:32
Each i IS scoped to its location - I just amended it to log the i's as well and as you can see - each log shows its place in the sequence - 0/0 , 0,1 , 1,0 ,11 - or in other words - for each of the i's in the first gtopu its calling the method and in the method - its iteratnig over the second list.
– gavgrif
Nov 26 '18 at 2:40
So, maybe I'm just missing the point. What would be different if you replaced all thelets withvars?
– Mark Meyer
Nov 26 '18 at 2:48
add a comment |
0
This is why let keyword is a better option than var- it keeps the scope to just the function or method that calls it.
The following snippet consoles -
0 / test 1 / 0 / test a
0 / test 1 / 1 / test b
1 / test 2 / 0 / test a
1 / test 2 / 1 / test b
ie: for each item of some_array - it calls someMethod and consoles the name of the first array as well as each iteration of the second array (other_array).
let some_array=[{id: '1', name: 'test 1'},{id: '2', name: 'test 2'}];
let other_array=[{id: 'a', name: 'test a'},{id: 'b', name: 'test b'}];
let length = some_array.length;
for (let i = 0; i < length; i ++) {
someMethod(i, some_array[i].name)
}
function someMethod(index, name) {
let length = other_array.length
for (let i = 0; i < length; i ++ ) {
console.log(index + ' / ' + name + ' / ' + i + ' / ' + other_array[i].name);
}
}answered Nov 26 '18 at 2:24
gavgrifgavgrif
8,6912918
1
I get the same output regardless ofletorvarhere. Maybe there's a better example?iinsidesomeMethodis scoped to the function.
– Mark Meyer
Nov 26 '18 at 2:32
Each i IS scoped to its location - I just amended it to log the i's as well and as you can see - each log shows its place in the sequence - 0/0 , 0,1 , 1,0 ,11 - or in other words - for each of the i's in the first gtopu its calling the method and in the method - its iteratnig over the second list.
– gavgrif
Nov 26 '18 at 2:40
So, maybe I'm just missing the point. What would be different if you replaced all thelets withvars?
– Mark Meyer
Nov 26 '18 at 2:48
add a comment |
0
0
0
This is why let keyword is a better option than var- it keeps the scope to just the function or method that calls it.
The following snippet consoles -
0 / test 1 / 0 / test a
0 / test 1 / 1 / test b
1 / test 2 / 0 / test a
1 / test 2 / 1 / test b
ie: for each item of some_array - it calls someMethod and consoles the name of the first array as well as each iteration of the second array (other_array).
let some_array=[{id: '1', name: 'test 1'},{id: '2', name: 'test 2'}];
let other_array=[{id: 'a', name: 'test a'},{id: 'b', name: 'test b'}];
let length = some_array.length;
for (let i = 0; i < length; i ++) {
someMethod(i, some_array[i].name)
}
function someMethod(index, name) {
let length = other_array.length
for (let i = 0; i < length; i ++ ) {
console.log(index + ' / ' + name + ' / ' + i + ' / ' + other_array[i].name);
}
}answered Nov 26 '18 at 2:24
gavgrifgavgrif
8,6912918
This is why let keyword is a better option than var- it keeps the scope to just the function or method that calls it.
The following snippet consoles -
0 / test 1 / 0 / test a
0 / test 1 / 1 / test b
1 / test 2 / 0 / test a
1 / test 2 / 1 / test b
ie: for each item of some_array - it calls someMethod and consoles the name of the first array as well as each iteration of the second array (other_array).
let some_array=[{id: '1', name: 'test 1'},{id: '2', name: 'test 2'}];
let other_array=[{id: 'a', name: 'test a'},{id: 'b', name: 'test b'}];
let length = some_array.length;
for (let i = 0; i < length; i ++) {
someMethod(i, some_array[i].name)
}
function someMethod(index, name) {
let length = other_array.length
for (let i = 0; i < length; i ++ ) {
console.log(index + ' / ' + name + ' / ' + i + ' / ' + other_array[i].name);
}
}let some_array=[{id: '1', name: 'test 1'},{id: '2', name: 'test 2'}];
let other_array=[{id: 'a', name: 'test a'},{id: 'b', name: 'test b'}];
let length = some_array.length;
for (let i = 0; i < length; i ++) {
someMethod(i, some_array[i].name)
}
function someMethod(index, name) {
let length = other_array.length
for (let i = 0; i < length; i ++ ) {
console.log(index + ' / ' + name + ' / ' + i + ' / ' + other_array[i].name);
}
}let some_array=[{id: '1', name: 'test 1'},{id: '2', name: 'test 2'}];
let other_array=[{id: 'a', name: 'test a'},{id: 'b', name: 'test b'}];
let length = some_array.length;
for (let i = 0; i < length; i ++) {
someMethod(i, some_array[i].name)
}
function someMethod(index, name) {
let length = other_array.length
for (let i = 0; i < length; i ++ ) {
console.log(index + ' / ' + name + ' / ' + i + ' / ' + other_array[i].name);
}
}answered Nov 26 '18 at 2:24
gavgrifgavgrif
8,6912918
edited Nov 26 '18 at 2:39
answered Nov 26 '18 at 2:24
gavgrifgavgrif
8,6912918
answered Nov 26 '18 at 2:24
gavgrifgavgrif
8,6912918
answered Nov 26 '18 at 2:24
gavgrifgavgrif
8,6912918
8,6912918
1
I get the same output regardless ofletorvarhere. Maybe there's a better example?iinsidesomeMethodis scoped to the function.
– Mark Meyer
Nov 26 '18 at 2:32
Each i IS scoped to its location - I just amended it to log the i's as well and as you can see - each log shows its place in the sequence - 0/0 , 0,1 , 1,0 ,11 - or in other words - for each of the i's in the first gtopu its calling the method and in the method - its iteratnig over the second list.
– gavgrif
Nov 26 '18 at 2:40
So, maybe I'm just missing the point. What would be different if you replaced all thelets withvars?
– Mark Meyer
Nov 26 '18 at 2:48
add a comment |
1
I get the same output regardless ofletorvarhere. Maybe there's a better example?iinsidesomeMethodis scoped to the function.
– Mark Meyer
Nov 26 '18 at 2:32
Each i IS scoped to its location - I just amended it to log the i's as well and as you can see - each log shows its place in the sequence - 0/0 , 0,1 , 1,0 ,11 - or in other words - for each of the i's in the first gtopu its calling the method and in the method - its iteratnig over the second list.
– gavgrif
Nov 26 '18 at 2:40
So, maybe I'm just missing the point. What would be different if you replaced all thelets withvars?
– Mark Meyer
Nov 26 '18 at 2:48
1
1
I get the same output regardless of
let or var here. Maybe there's a better example? i inside someMethod is scoped to the function.– Mark Meyer
Nov 26 '18 at 2:32
I get the same output regardless of
let or var here. Maybe there's a better example? i inside someMethod is scoped to the function.– Mark Meyer
Nov 26 '18 at 2:32
Each i IS scoped to its location - I just amended it to log the i's as well and as you can see - each log shows its place in the sequence - 0/0 , 0,1 , 1,0 ,11 - or in other words - for each of the i's in the first gtopu its calling the method and in the method - its iteratnig over the second list.
– gavgrif
Nov 26 '18 at 2:40
Each i IS scoped to its location - I just amended it to log the i's as well and as you can see - each log shows its place in the sequence - 0/0 , 0,1 , 1,0 ,11 - or in other words - for each of the i's in the first gtopu its calling the method and in the method - its iteratnig over the second list.
– gavgrif
Nov 26 '18 at 2:40
So, maybe I'm just missing the point. What would be different if you replaced all the
lets with vars?– Mark Meyer
Nov 26 '18 at 2:48
So, maybe I'm just missing the point. What would be different if you replaced all the
lets with vars?– Mark Meyer
Nov 26 '18 at 2:48
add a comment |
0
SCOPE
In JavaScript there are two types of scope:
Local scope
Global scope
JavaScript has function scope: Each function creates a new scope.
let allows you to declare variables that are limited in scope to the block.
Notice how var create a property on the global object but let is undefined.
var x = 'global';
let y = 'global';
console.log(this.x); // "global"
console.log(this.y); // undefined
Let's try it with your code.
let some_array = [{ name: 'Angel' }, { name: 'James' }]
let other_array = ['0','1'];
//let i is declared local
for (let i = 0; i < some_array.length; i++) {
someMethod(some_array[i].name) //"let" some_array variable is required here to the local "for loop" scope.
}
function someMethod(name) {
//let i is declared local here again so it's considered a new variable i.
for (let i = 0; i < some_array.length; i++) {
console.log(name)
}
}
For more examples about scope in Javascript
answered Nov 26 '18 at 2:42
Angel RomaAngel Roma
19829
Wouldn'tvar ialso be local tosomeMethod()?
– Mark Meyer
Nov 26 '18 at 2:50
@MarkMeyerletgives you the privilege to declare variables that are limited in scope to the block, statement of expression unlikevar.varis rather a keyword which defines a variable globally regardless of block scope
– Angel Roma
Nov 26 '18 at 2:55
That's not quite correct. Inside a functionvaris scoped to that function.
– Mark Meyer
Nov 26 '18 at 3:01
varkeyword defines a variable globally regardless of block scope.
– Angel Roma
Nov 26 '18 at 3:06
But it doesn't define it globally when used inside a function. In the example you have, it makes no difference whether you useletorvarforibecause the second one is defined inside the functionsomeMethod. It will be a distinct variable unrelated to theioutside the function. Nothing changes if you usevarinstead ofletin your example.
– Mark Meyer
Nov 26 '18 at 3:11
add a comment |
0
SCOPE
In JavaScript there are two types of scope:
Local scope
Global scope
JavaScript has function scope: Each function creates a new scope.
let allows you to declare variables that are limited in scope to the block.
Notice how var create a property on the global object but let is undefined.
var x = 'global';
let y = 'global';
console.log(this.x); // "global"
console.log(this.y); // undefined
Let's try it with your code.
let some_array = [{ name: 'Angel' }, { name: 'James' }]
let other_array = ['0','1'];
//let i is declared local
for (let i = 0; i < some_array.length; i++) {
someMethod(some_array[i].name) //"let" some_array variable is required here to the local "for loop" scope.
}
function someMethod(name) {
//let i is declared local here again so it's considered a new variable i.
for (let i = 0; i < some_array.length; i++) {
console.log(name)
}
}
For more examples about scope in Javascript
answered Nov 26 '18 at 2:42
Angel RomaAngel Roma
19829
Wouldn'tvar ialso be local tosomeMethod()?
– Mark Meyer
Nov 26 '18 at 2:50
@MarkMeyerletgives you the privilege to declare variables that are limited in scope to the block, statement of expression unlikevar.varis rather a keyword which defines a variable globally regardless of block scope
– Angel Roma
Nov 26 '18 at 2:55
That's not quite correct. Inside a functionvaris scoped to that function.
– Mark Meyer
Nov 26 '18 at 3:01
varkeyword defines a variable globally regardless of block scope.
– Angel Roma
Nov 26 '18 at 3:06
But it doesn't define it globally when used inside a function. In the example you have, it makes no difference whether you useletorvarforibecause the second one is defined inside the functionsomeMethod. It will be a distinct variable unrelated to theioutside the function. Nothing changes if you usevarinstead ofletin your example.
– Mark Meyer
Nov 26 '18 at 3:11
add a comment |
0
0
0
SCOPE
In JavaScript there are two types of scope:
Local scope
Global scope
JavaScript has function scope: Each function creates a new scope.
let allows you to declare variables that are limited in scope to the block.
Notice how var create a property on the global object but let is undefined.
var x = 'global';
let y = 'global';
console.log(this.x); // "global"
console.log(this.y); // undefined
Let's try it with your code.
let some_array = [{ name: 'Angel' }, { name: 'James' }]
let other_array = ['0','1'];
//let i is declared local
for (let i = 0; i < some_array.length; i++) {
someMethod(some_array[i].name) //"let" some_array variable is required here to the local "for loop" scope.
}
function someMethod(name) {
//let i is declared local here again so it's considered a new variable i.
for (let i = 0; i < some_array.length; i++) {
console.log(name)
}
}
For more examples about scope in Javascript
answered Nov 26 '18 at 2:42
Angel RomaAngel Roma
19829
SCOPE
In JavaScript there are two types of scope:
Local scope
Global scope
JavaScript has function scope: Each function creates a new scope.
let allows you to declare variables that are limited in scope to the block.
Notice how var create a property on the global object but let is undefined.
var x = 'global';
let y = 'global';
console.log(this.x); // "global"
console.log(this.y); // undefined
Let's try it with your code.
let some_array = [{ name: 'Angel' }, { name: 'James' }]
let other_array = ['0','1'];
//let i is declared local
for (let i = 0; i < some_array.length; i++) {
someMethod(some_array[i].name) //"let" some_array variable is required here to the local "for loop" scope.
}
function someMethod(name) {
//let i is declared local here again so it's considered a new variable i.
for (let i = 0; i < some_array.length; i++) {
console.log(name)
}
}
For more examples about scope in Javascript
answered Nov 26 '18 at 2:42
Angel RomaAngel Roma
19829
answered Nov 26 '18 at 2:42
Angel RomaAngel Roma
19829
answered Nov 26 '18 at 2:42
Angel RomaAngel Roma
19829
answered Nov 26 '18 at 2:42
Angel RomaAngel Roma
19829
19829
Wouldn'tvar ialso be local tosomeMethod()?
– Mark Meyer
Nov 26 '18 at 2:50
@MarkMeyerletgives you the privilege to declare variables that are limited in scope to the block, statement of expression unlikevar.varis rather a keyword which defines a variable globally regardless of block scope
– Angel Roma
Nov 26 '18 at 2:55
That's not quite correct. Inside a functionvaris scoped to that function.
– Mark Meyer
Nov 26 '18 at 3:01
varkeyword defines a variable globally regardless of block scope.
– Angel Roma
Nov 26 '18 at 3:06
But it doesn't define it globally when used inside a function. In the example you have, it makes no difference whether you useletorvarforibecause the second one is defined inside the functionsomeMethod. It will be a distinct variable unrelated to theioutside the function. Nothing changes if you usevarinstead ofletin your example.
– Mark Meyer
Nov 26 '18 at 3:11
add a comment |
Wouldn'tvar ialso be local tosomeMethod()?
– Mark Meyer
Nov 26 '18 at 2:50
@MarkMeyerletgives you the privilege to declare variables that are limited in scope to the block, statement of expression unlikevar.varis rather a keyword which defines a variable globally regardless of block scope
– Angel Roma
Nov 26 '18 at 2:55
That's not quite correct. Inside a functionvaris scoped to that function.
– Mark Meyer
Nov 26 '18 at 3:01
varkeyword defines a variable globally regardless of block scope.
– Angel Roma
Nov 26 '18 at 3:06
But it doesn't define it globally when used inside a function. In the example you have, it makes no difference whether you useletorvarforibecause the second one is defined inside the functionsomeMethod. It will be a distinct variable unrelated to theioutside the function. Nothing changes if you usevarinstead ofletin your example.
– Mark Meyer
Nov 26 '18 at 3:11
Wouldn't
var i also be local to someMethod()?– Mark Meyer
Nov 26 '18 at 2:50
Wouldn't
var i also be local to someMethod()?– Mark Meyer
Nov 26 '18 at 2:50
@MarkMeyer
let gives you the privilege to declare variables that are limited in scope to the block, statement of expression unlike var. var is rather a keyword which defines a variable globally regardless of block scope– Angel Roma
Nov 26 '18 at 2:55
@MarkMeyer
let gives you the privilege to declare variables that are limited in scope to the block, statement of expression unlike var. var is rather a keyword which defines a variable globally regardless of block scope– Angel Roma
Nov 26 '18 at 2:55
That's not quite correct. Inside a function
var is scoped to that function.– Mark Meyer
Nov 26 '18 at 3:01
That's not quite correct. Inside a function
var is scoped to that function.– Mark Meyer
Nov 26 '18 at 3:01
var keyword defines a variable globally regardless of block scope.– Angel Roma
Nov 26 '18 at 3:06
var keyword defines a variable globally regardless of block scope.– Angel Roma
Nov 26 '18 at 3:06
But it doesn't define it globally when used inside a function. In the example you have, it makes no difference whether you use
let or var for i because the second one is defined inside the function someMethod. It will be a distinct variable unrelated to the i outside the function. Nothing changes if you use var instead of let in your example.– Mark Meyer
Nov 26 '18 at 3:11
But it doesn't define it globally when used inside a function. In the example you have, it makes no difference whether you use
let or var for i because the second one is defined inside the function someMethod. It will be a distinct variable unrelated to the i outside the function. Nothing changes if you use var instead of let in your example.– Mark Meyer
Nov 26 '18 at 3:11
add a comment |
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3
Take a look at the
letkeyword.– ggorlen
Nov 26 '18 at 2:21
2
The code above doesn't run properly because the inner i and length carry over to the outer levelno, they don't - you must be doing something else wrong– Jaromanda X
Nov 26 '18 at 2:40