JavaScript "associative" array access

The key can be a dynamically computed string. Give an example of something you pass that doesn't work.

Given:

var bowl = {}; // empty object

You can say:

bowl["fruit"] = "apple";

Or:

bowl.fruit = "apple"; // NB. `fruit` is not a string variable here

Or even:

var fruit = "fruit";
bowl[fruit] = "apple"; // now it is a string variable! Note the [ ]

Or if you really want to:

bowl["f" + "r" + "u" + "i" + "t"] = "apple";

Those all have the same effect on the bowl object. And then you can use the corresponding patterns to retrieve values:

var value = bowl["fruit"];
var value = bowl.fruit; // fruit is a hard-coded property name
var value = bowl[fruit]; // fruit must be a variable containing the string "fruit"
var value = bowl["f" + "r" + "u" + "i" + "t"];