Get global variable dynamically by name string in JavaScript

<script>

//in one script

var someVarName_10 = 20;

</script>

I want to get access to this variable from another script by name of variable. With window object its simple, is it possible with local variable?

I mean access this var by code like this:

<script>

  alert(all_vars['someVar' + 'Name' + num]);

</script>

edited Jan 12 '16 at 19:18

Michał Perłakowski

42.2k1699115

asked Dec 17 '09 at 10:43

appqui-platform

1,94763458

1

Your sample shows a global variable. You want to know if you can access it from a local scope?

– Crescent Fresh
Dec 17 '09 at 10:46

It really depends on what you mean by 'local scope'.. Javascript functions are scoped only to functions, not blocks or even files

– K Prime
Dec 17 '09 at 10:50

possible duplicate of Is there a way to access a javascript variable using a string that contains the name of the variable?

– Gilles
May 29 '11 at 20:56

add a comment |

<script>

//in one script

var someVarName_10 = 20;

</script>

I want to get access to this variable from another script by name of variable. With window object its simple, is it possible with local variable?

I mean access this var by code like this:

<script>

  alert(all_vars['someVar' + 'Name' + num]);

</script>

edited Jan 12 '16 at 19:18

Michał Perłakowski

42.2k1699115

asked Dec 17 '09 at 10:43

appqui-platform

1,94763458

1

Your sample shows a global variable. You want to know if you can access it from a local scope?

– Crescent Fresh
Dec 17 '09 at 10:46

It really depends on what you mean by 'local scope'.. Javascript functions are scoped only to functions, not blocks or even files

– K Prime
Dec 17 '09 at 10:50

possible duplicate of Is there a way to access a javascript variable using a string that contains the name of the variable?

– Gilles
May 29 '11 at 20:56

add a comment |

<script>

//in one script

var someVarName_10 = 20;

</script>

I want to get access to this variable from another script by name of variable. With window object its simple, is it possible with local variable?

I mean access this var by code like this:

<script>

  alert(all_vars['someVar' + 'Name' + num]);

</script>

edited Jan 12 '16 at 19:18

Michał Perłakowski

42.2k1699115

asked Dec 17 '09 at 10:43

appqui-platform

1,94763458

<script>

//in one script

var someVarName_10 = 20;

</script>

I want to get access to this variable from another script by name of variable. With window object its simple, is it possible with local variable?

I mean access this var by code like this:

<script>

  alert(all_vars['someVar' + 'Name' + num]);

</script>

javascript

edited Jan 12 '16 at 19:18

Michał Perłakowski

42.2k1699115

asked Dec 17 '09 at 10:43

appqui-platform

1,94763458

edited Jan 12 '16 at 19:18

Michał Perłakowski

42.2k1699115

asked Dec 17 '09 at 10:43

appqui-platform

1,94763458

edited Jan 12 '16 at 19:18

Michał Perłakowski

42.2k1699115

edited Jan 12 '16 at 19:18

Michał Perłakowski

42.2k1699115

edited Jan 12 '16 at 19:18

Michał Perłakowski

42.2k1699115

asked Dec 17 '09 at 10:43

appqui-platform

1,94763458

asked Dec 17 '09 at 10:43

appqui-platform

1,94763458

asked Dec 17 '09 at 10:43

appqui-platform

1,94763458

1

Your sample shows a global variable. You want to know if you can access it from a local scope?

– Crescent Fresh
Dec 17 '09 at 10:46

It really depends on what you mean by 'local scope'.. Javascript functions are scoped only to functions, not blocks or even files

– K Prime
Dec 17 '09 at 10:50

possible duplicate of Is there a way to access a javascript variable using a string that contains the name of the variable?

– Gilles
May 29 '11 at 20:56

add a comment |

1

Your sample shows a global variable. You want to know if you can access it from a local scope?

– Crescent Fresh
Dec 17 '09 at 10:46

It really depends on what you mean by 'local scope'.. Javascript functions are scoped only to functions, not blocks or even files

– K Prime
Dec 17 '09 at 10:50

possible duplicate of Is there a way to access a javascript variable using a string that contains the name of the variable?

– Gilles
May 29 '11 at 20:56

Your sample shows a global variable. You want to know if you can access it from a local scope?

– Crescent Fresh
Dec 17 '09 at 10:46

It really depends on what you mean by 'local scope'.. Javascript functions are scoped only to functions, not blocks or even files

– K Prime
Dec 17 '09 at 10:50

possible duplicate of Is there a way to access a javascript variable using a string that contains the name of the variable?

– Gilles
May 29 '11 at 20:56

add a comment |

5 Answers
5

active

oldest

votes

Do you want to do something like this?

<script>

//in one script

var someVarName_10 = 20;



alert(window["someVarName_10"]); //alert 20



</script>

Update: because OP edited the question.

<script>

  num=10;

  alert(window['someVar' + 'Name_' + num]); //alert 20

</script>

answered Dec 17 '09 at 10:53

YOU

84.7k20151199

sorry, I was wrong, i thought that vars are not in window, thanks

– appqui-platform
Dec 17 '09 at 10:59

you're welcome.

– YOU
Dec 17 '09 at 11:00

5

I don't care what OP actually wanted. I care about what is in question title and therefore becomes google result in my searches.

– Tomáš Zato
Oct 22 '15 at 8:15

1

@DeepakChaudhary, may be you want something like lodash's _.get? - lodash.com/docs#get

– YOU
Aug 2 '16 at 15:45

1

That would be window["a"].name;

– Repo
Mar 28 '17 at 8:13

|
show 4 more comments

I've noticed that everyone is advising global var creation this will lead to variables leak to global namespace.
When you dynamically creating classnames or just variables it's easy to keep em local:

this['className'] = 123;

this['varName'] = 123;

Name-spacing would look like this:

vars = {};

vars['varName'] = 123;

vars.varName // 123

edited Jul 2 '13 at 17:09

yckart

20.7k593107

answered Sep 8 '12 at 21:08

Andrew Shatnyy

1,1111019

1

var this['className'] = 123; looks like a syntax error to me.

– Felix Kling
Jan 19 '13 at 1:33

you right i don't know why I added var

– Andrew Shatnyy
Apr 7 '13 at 19:54

1

This is better than accepted answer. More descriptive about how this feature works in class scopes.

– Sellorio
Jun 22 '15 at 1:54

add a comment |

<script>

    var someVarName_10 = 20;

    var num = 10;

    alert(eval('someVar' + 'Name_' + num)); //alert 20

</script>

answered Jan 16 '15 at 16:39

Matteo Baroni

10913

eval worked better for me! but use it with caution

– papaiatis
Nov 9 '16 at 13:14

add a comment |

well, for debugging purpose only, you could do something like this. I use it during the development of classes, where some variables must remain private (var). this work even in local variable (and global of curse)

function MYCLASS(){

    var a=1, b=2, c=3;

    this.public = "variable";

    this.debug = function(sVar){

        return eval(sVar);

    }

}



var myThing = new MYCLASS();

myThing.debug('a') //return 1

myThing.debug('b') //return 2

myThing.debug('c') //return 3

answered Sep 16 '15 at 15:38

Nereo Costacurta

1,55831423

add a comment |

-5

If this is what you said:

<script type="text/javascript">

var hello = 'test';

</script>

<script type="text/javascript">

  alert (hello);

</script>

It works because script are finally available to the document and you can access their vars.

answered Dec 17 '09 at 10:46

Sarfraz

299k64471547

add a comment |

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5 Answers
5

active

oldest

votes

5 Answers
5

active

oldest

votes

Do you want to do something like this?

<script>

//in one script

var someVarName_10 = 20;



alert(window["someVarName_10"]); //alert 20



</script>

Update: because OP edited the question.

<script>

  num=10;

  alert(window['someVar' + 'Name_' + num]); //alert 20

</script>

answered Dec 17 '09 at 10:53

YOU

84.7k20151199

sorry, I was wrong, i thought that vars are not in window, thanks

– appqui-platform
Dec 17 '09 at 10:59

you're welcome.

– YOU
Dec 17 '09 at 11:00

5

I don't care what OP actually wanted. I care about what is in question title and therefore becomes google result in my searches.

– Tomáš Zato
Oct 22 '15 at 8:15

1

@DeepakChaudhary, may be you want something like lodash's _.get? - lodash.com/docs#get

– YOU
Aug 2 '16 at 15:45

1

That would be window["a"].name;

– Repo
Mar 28 '17 at 8:13

|
show 4 more comments

Do you want to do something like this?

<script>

//in one script

var someVarName_10 = 20;



alert(window["someVarName_10"]); //alert 20



</script>

Update: because OP edited the question.

<script>

  num=10;

  alert(window['someVar' + 'Name_' + num]); //alert 20

</script>

answered Dec 17 '09 at 10:53

YOU

84.7k20151199

sorry, I was wrong, i thought that vars are not in window, thanks

– appqui-platform
Dec 17 '09 at 10:59

you're welcome.

– YOU
Dec 17 '09 at 11:00

5

I don't care what OP actually wanted. I care about what is in question title and therefore becomes google result in my searches.

– Tomáš Zato
Oct 22 '15 at 8:15

1

@DeepakChaudhary, may be you want something like lodash's _.get? - lodash.com/docs#get

– YOU
Aug 2 '16 at 15:45

1

That would be window["a"].name;

– Repo
Mar 28 '17 at 8:13

|
show 4 more comments

Do you want to do something like this?

<script>

//in one script

var someVarName_10 = 20;



alert(window["someVarName_10"]); //alert 20



</script>

Update: because OP edited the question.

<script>

  num=10;

  alert(window['someVar' + 'Name_' + num]); //alert 20

</script>

answered Dec 17 '09 at 10:53

YOU

84.7k20151199

Do you want to do something like this?

<script>

//in one script

var someVarName_10 = 20;



alert(window["someVarName_10"]); //alert 20



</script>

Update: because OP edited the question.

<script>

  num=10;

  alert(window['someVar' + 'Name_' + num]); //alert 20

</script>

answered Dec 17 '09 at 10:53

YOU

84.7k20151199

answered Dec 17 '09 at 10:53

YOU

84.7k20151199

answered Dec 17 '09 at 10:53

YOU

84.7k20151199

answered Dec 17 '09 at 10:53

YOU

84.7k20151199

sorry, I was wrong, i thought that vars are not in window, thanks

– appqui-platform
Dec 17 '09 at 10:59

you're welcome.

– YOU
Dec 17 '09 at 11:00

5

I don't care what OP actually wanted. I care about what is in question title and therefore becomes google result in my searches.

– Tomáš Zato
Oct 22 '15 at 8:15

1

@DeepakChaudhary, may be you want something like lodash's _.get? - lodash.com/docs#get

– YOU
Aug 2 '16 at 15:45

1

That would be window["a"].name;

– Repo
Mar 28 '17 at 8:13

|
show 4 more comments

sorry, I was wrong, i thought that vars are not in window, thanks

– appqui-platform
Dec 17 '09 at 10:59

you're welcome.

– YOU
Dec 17 '09 at 11:00

5

I don't care what OP actually wanted. I care about what is in question title and therefore becomes google result in my searches.

– Tomáš Zato
Oct 22 '15 at 8:15

1

@DeepakChaudhary, may be you want something like lodash's _.get? - lodash.com/docs#get

– YOU
Aug 2 '16 at 15:45

1

That would be window["a"].name;

– Repo
Mar 28 '17 at 8:13

sorry, I was wrong, i thought that vars are not in window, thanks

– appqui-platform
Dec 17 '09 at 10:59

you're welcome.

– YOU
Dec 17 '09 at 11:00

I don't care what OP actually wanted. I care about what is in question title and therefore becomes google result in my searches.

– Tomáš Zato
Oct 22 '15 at 8:15

@DeepakChaudhary, may be you want something like lodash's _.get? - lodash.com/docs#get

– YOU
Aug 2 '16 at 15:45

That would be window["a"].name;

– Repo
Mar 28 '17 at 8:13

|
show 4 more comments

I've noticed that everyone is advising global var creation this will lead to variables leak to global namespace.
When you dynamically creating classnames or just variables it's easy to keep em local:

this['className'] = 123;

this['varName'] = 123;

Name-spacing would look like this:

vars = {};

vars['varName'] = 123;

vars.varName // 123

edited Jul 2 '13 at 17:09

yckart

20.7k593107

answered Sep 8 '12 at 21:08

Andrew Shatnyy

1,1111019

1

var this['className'] = 123; looks like a syntax error to me.

– Felix Kling
Jan 19 '13 at 1:33

you right i don't know why I added var

– Andrew Shatnyy
Apr 7 '13 at 19:54

1

This is better than accepted answer. More descriptive about how this feature works in class scopes.

– Sellorio
Jun 22 '15 at 1:54

add a comment |

I've noticed that everyone is advising global var creation this will lead to variables leak to global namespace.
When you dynamically creating classnames or just variables it's easy to keep em local:

this['className'] = 123;

this['varName'] = 123;

Name-spacing would look like this:

vars = {};

vars['varName'] = 123;

vars.varName // 123

edited Jul 2 '13 at 17:09

yckart

20.7k593107

answered Sep 8 '12 at 21:08

Andrew Shatnyy

1,1111019

1

var this['className'] = 123; looks like a syntax error to me.

– Felix Kling
Jan 19 '13 at 1:33

you right i don't know why I added var

– Andrew Shatnyy
Apr 7 '13 at 19:54

1

This is better than accepted answer. More descriptive about how this feature works in class scopes.

– Sellorio
Jun 22 '15 at 1:54

add a comment |

I've noticed that everyone is advising global var creation this will lead to variables leak to global namespace.
When you dynamically creating classnames or just variables it's easy to keep em local:

this['className'] = 123;

this['varName'] = 123;

Name-spacing would look like this:

vars = {};

vars['varName'] = 123;

vars.varName // 123

edited Jul 2 '13 at 17:09

yckart

20.7k593107

answered Sep 8 '12 at 21:08

Andrew Shatnyy

1,1111019

I've noticed that everyone is advising global var creation this will lead to variables leak to global namespace.
When you dynamically creating classnames or just variables it's easy to keep em local:

this['className'] = 123;

this['varName'] = 123;

Name-spacing would look like this:

vars = {};

vars['varName'] = 123;

vars.varName // 123

edited Jul 2 '13 at 17:09

yckart

20.7k593107

answered Sep 8 '12 at 21:08

Andrew Shatnyy

1,1111019

edited Jul 2 '13 at 17:09

yckart

20.7k593107

edited Jul 2 '13 at 17:09

yckart

20.7k593107

edited Jul 2 '13 at 17:09

yckart

20.7k593107

answered Sep 8 '12 at 21:08

Andrew Shatnyy

1,1111019

answered Sep 8 '12 at 21:08

Andrew Shatnyy

1,1111019

answered Sep 8 '12 at 21:08

Andrew Shatnyy

1,1111019

1

var this['className'] = 123; looks like a syntax error to me.

– Felix Kling
Jan 19 '13 at 1:33

you right i don't know why I added var

– Andrew Shatnyy
Apr 7 '13 at 19:54

1

This is better than accepted answer. More descriptive about how this feature works in class scopes.

– Sellorio
Jun 22 '15 at 1:54

add a comment |

1

var this['className'] = 123; looks like a syntax error to me.

– Felix Kling
Jan 19 '13 at 1:33

you right i don't know why I added var

– Andrew Shatnyy
Apr 7 '13 at 19:54

1

This is better than accepted answer. More descriptive about how this feature works in class scopes.

– Sellorio
Jun 22 '15 at 1:54

var this['className'] = 123; looks like a syntax error to me.

– Felix Kling
Jan 19 '13 at 1:33

you right i don't know why I added var

– Andrew Shatnyy
Apr 7 '13 at 19:54

This is better than accepted answer. More descriptive about how this feature works in class scopes.

– Sellorio
Jun 22 '15 at 1:54

add a comment |

<script>

    var someVarName_10 = 20;

    var num = 10;

    alert(eval('someVar' + 'Name_' + num)); //alert 20

</script>

answered Jan 16 '15 at 16:39

Matteo Baroni

10913

eval worked better for me! but use it with caution

– papaiatis
Nov 9 '16 at 13:14

add a comment |

<script>

    var someVarName_10 = 20;

    var num = 10;

    alert(eval('someVar' + 'Name_' + num)); //alert 20

</script>

answered Jan 16 '15 at 16:39

Matteo Baroni

10913

eval worked better for me! but use it with caution

– papaiatis
Nov 9 '16 at 13:14

add a comment |

<script>

    var someVarName_10 = 20;

    var num = 10;

    alert(eval('someVar' + 'Name_' + num)); //alert 20

</script>

answered Jan 16 '15 at 16:39

Matteo Baroni

10913

<script>

    var someVarName_10 = 20;

    var num = 10;

    alert(eval('someVar' + 'Name_' + num)); //alert 20

</script>

answered Jan 16 '15 at 16:39

Matteo Baroni

10913

answered Jan 16 '15 at 16:39

Matteo Baroni

10913

answered Jan 16 '15 at 16:39

Matteo Baroni

10913

answered Jan 16 '15 at 16:39

Matteo Baroni

10913

eval worked better for me! but use it with caution

– papaiatis
Nov 9 '16 at 13:14

add a comment |

eval worked better for me! but use it with caution

– papaiatis
Nov 9 '16 at 13:14

eval worked better for me! but use it with caution

– papaiatis
Nov 9 '16 at 13:14

add a comment |

function MYCLASS(){

    var a=1, b=2, c=3;

    this.public = "variable";

    this.debug = function(sVar){

        return eval(sVar);

    }

}



var myThing = new MYCLASS();

myThing.debug('a') //return 1

myThing.debug('b') //return 2

myThing.debug('c') //return 3

answered Sep 16 '15 at 15:38

Nereo Costacurta

1,55831423

add a comment |

function MYCLASS(){

    var a=1, b=2, c=3;

    this.public = "variable";

    this.debug = function(sVar){

        return eval(sVar);

    }

}



var myThing = new MYCLASS();

myThing.debug('a') //return 1

myThing.debug('b') //return 2

myThing.debug('c') //return 3

answered Sep 16 '15 at 15:38

Nereo Costacurta

1,55831423

add a comment |

function MYCLASS(){

    var a=1, b=2, c=3;

    this.public = "variable";

    this.debug = function(sVar){

        return eval(sVar);

    }

}



var myThing = new MYCLASS();

myThing.debug('a') //return 1

myThing.debug('b') //return 2

myThing.debug('c') //return 3

answered Sep 16 '15 at 15:38

Nereo Costacurta

1,55831423

function MYCLASS(){

    var a=1, b=2, c=3;

    this.public = "variable";

    this.debug = function(sVar){

        return eval(sVar);

    }

}



var myThing = new MYCLASS();

myThing.debug('a') //return 1

myThing.debug('b') //return 2

myThing.debug('c') //return 3

answered Sep 16 '15 at 15:38

Nereo Costacurta

1,55831423

answered Sep 16 '15 at 15:38

Nereo Costacurta

1,55831423

answered Sep 16 '15 at 15:38

Nereo Costacurta

1,55831423

answered Sep 16 '15 at 15:38

Nereo Costacurta

1,55831423

add a comment |

-5

If this is what you said:

<script type="text/javascript">

var hello = 'test';

</script>

<script type="text/javascript">

  alert (hello);

</script>

It works because script are finally available to the document and you can access their vars.

answered Dec 17 '09 at 10:46

Sarfraz

299k64471547

add a comment |

-5

If this is what you said:

<script type="text/javascript">

var hello = 'test';

</script>

<script type="text/javascript">

  alert (hello);

</script>

It works because script are finally available to the document and you can access their vars.

answered Dec 17 '09 at 10:46

Sarfraz

299k64471547

add a comment |

-5

If this is what you said:

<script type="text/javascript">

var hello = 'test';

</script>

<script type="text/javascript">

  alert (hello);

</script>

It works because script are finally available to the document and you can access their vars.

answered Dec 17 '09 at 10:46

Sarfraz

299k64471547

If this is what you said:

<script type="text/javascript">

var hello = 'test';

</script>

<script type="text/javascript">

  alert (hello);

</script>

It works because script are finally available to the document and you can access their vars.

answered Dec 17 '09 at 10:46

Sarfraz

299k64471547

answered Dec 17 '09 at 10:46

Sarfraz

299k64471547

answered Dec 17 '09 at 10:46

Sarfraz

299k64471547

answered Dec 17 '09 at 10:46

Sarfraz

299k64471547

add a comment |

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