Javascript use variable as object name

Question

I want to use the value of a variable to access an object   Let s say I have an object named myobject   I want to fill a variable with this name and use the variable to access the object   Example   var objname    myobject    objname  value    value

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You could use eval   eval variablename     value    value

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You can t do this in general  except at the window scope  where you can write window objname  value    value

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When using the window objname   please make sure the objname is global variables  Otherwise  will work sometime  and fail sometimes  window objname  value

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If object is in some namespace ie  Company Module Components Foo you can use this function   CoffeeScript     objByName   name  context   window  - gt      ns   name split         func   context     for n  i in ns         func   func n      return func   Resulted Js     objByName  function name  context      var func  i  n  ns   i   len    if  context    null        context   window        ns   name split         func   context    for  i    i   0   len   ns length   i  lt   len  i      i        n   ns i       func   func n         return func      Then you can create a new object or do whatever  Note the parenthises through   var o   new  objByName  Company Module Components Foo    objByName  some deeply nested object   value   This idea is borrowed from similar question  How to execute a JavaScript function when I have its name as a string

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Is it a global variable  If so  these are actually part of the window object  so you can do window objname  value   If it s local to a function  I don t think there s a good way to do what you want

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You can set an objects property this way    x000D   x000D  var obj       x000D  obj whateverVarName    yourVal   x000D  console log obj   x000D   x000D   x000D

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Global   myObject     value  0    anObjectName    myObject   this anObjectName  value     console log this anObjectName      Global  v2  var anObjectName    myObject   this anObjectName     myvalue   console log myObject    Local  v1   function         var scope   this       if  scope    arguments callee            arguments callee call arguments callee           return false             scope myObject     value  0        scope anObjectName    myObject       scope scope anObjectName  value         console log scope myObject value           Local  v2   function           var scope   this       scope myObject     value  0        scope anObjectName    myObject       scope scope anObjectName  value         console log scope myObject value          call

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Use square bracket around variable name    var objname    myobject     objname   value    value

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The object exists in some scope  so you can almost always access the variable via this syntax   var objname    myobject   containing scope reference objname  some property    some value     The only place where this gets tricky is when you are in a closed scope and you want access to a top-level local variable    When you have something like this    function        var some variable    value  25       var x    some variable       console log this x   window x       Doesn t work         You can get around that by using eval instead to access the current scope chain     but I don t recommend it unless you ve done a lot of testing and you know that that s the best way to go about things    function        var some variable    value  25       var x    some variable       eval x  value   42      console log some variable      Works         Your best bet is to have a reference to a name in an always-going-to-be-there object  like this in the global scope or a private top-level variable in a local scope  and put everything else in there   Thus   var my outer variable       var outer pointer    my outer variable      Reach my outer variable with this outer pointer     or window outer pointer    function        var my inner scope     my inner variable             var inner pointer    my inner variable          Reach my inner variable by using        my inner scope inner pointer

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I think Shaz s answer for local variables is hard to understand  though it works for non-recursive functions  Here s another way that I think it s clearer  but it s still his idea  exact same behavior   It s also not accessing the local variables dynamically  just the property of the local variable   Essentially  it s using a global variable  attached to the function object      Here s  a version of it that is more straight forward  function doIt         doIt objname           var someObject    objname       doIt someObject  value    value           console log doIt objname           Which is essentially the same thing as creating a global to store the variable  so you can access it as a property  Creating a global to do this is such a hack   Here s a cleaner hack that doesn t create global variables  it uses a local variable instead   function doIt       var scope          MyProp   Hello         var name    MyProp     console log scope name        See Javascript  interpret string as object reference

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let players       players something        players something  somethingElse    test   console log players      -    something    somethingElse   test

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One of the challenges I had with the answers is that it assumed that the object was a single level  For example   const testObj     testKey   testValue    const refString    testKey   const refObj   testObj refString     works fine  but  const testObj     testKey                      level2Key   level2Value                      const refString    testKey level2Key   const refObj   testObj refString     does not work   What I ended up doing was building a function to access multi-level objects   objVar str        let obj   this      const parts   str split           for  let p of parts            obj   obj p             return obj      In the second scenario  then  I can pass the string to this function to get back the object I m looking for   const testObj     testKey                      level2Key   level2Value                      const refString    testObj testKey level2Key   const refObj   objVar refString

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If you already know the list of the possible varible names then try creating a new Object iconObj  whose properties name are same as object names   Here in below example  iconLib variable will hold two string values   either  ZondIcons  or  MaterialIcons    propertyName is the property of ZondIcons or MaterialsIcon object      const iconObj         ZondIcons      MaterialIcons        const objValue   iconObj iconLib  propertyName

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var micro    test   hello      var device    test    console log micro device

[javascript] Javascript use variable as object name

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