NodeJS: Passing a variable into a different variable's name

Question

How would I create a function that accepts a value and creates a watchfile listener based on that value received?

Example of what I'm trying to do:

function createListener(id) {
  var listener(id here) = fs.watchFile(file, function () {
  });
});

How could I place the id given to function createListener(); into the listener's assigned variable?

Example: createListener('5'); would create var listener5 = fs.watchFile();

createListener('23'); would create var listener23 = fs.watchFile();

Are you sure that's what you're after? Even if you could create it, the variable would be local to the function. Would an object with the key set to the id not suffice? Then you can do watching = {}; watching[id] = fs.watchFile(); var listener = watching[id]; — Philip Ramirez
– Philip Ramirez, Commented Sep 27, 2012 at 4:39

jwchang · Accepted Answer · 2012-09-27 05:06:30Z

2

You can use eval to create dynamic variable names

but it is bad part of JavaScript and I strongly recommend not to use eval at all.

I recommend you to use either array or JSON objects to store multiple functions.

Array

var functions = [];
functions.push = function () { ... };

// functions = [ function () { ... } ];

JSON

var functions = {};
functions["one"] = function () { ... };

// functions = { one: function () { ... } };

answered Sep 27, 2012 at 5:06

jwchang

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