Javascript - use string as object reference

问题

If I have a bunch of objects, and within these objects is the string "id" (which is the same as the object name) how can I use this string to reference the object?

Example:

//These objects are tests - note the id's are the same as the object name

var test1 = {
    id : "test1",
    data : "Test 1 test 1 test 1"
}

var test2 = {
    id : "test2",
    data : "Test 2 test 2 test 2"
}


/* ----- My Function   ----- */

var myObj = null;

function setMyObj(obj){
   myObj = obj;
}

setMyObj(test1);

/* ----- My Function   ----- */

Now, if I call the following:

myObj.id;

The Result is "test1" (a string). If I want to use this to get the data from test1, how would I do so?

"myObj.id".data
[myObj.id].data

^^^

These don't work!

Cheers, Rich

回答1:

If your variables are defined on a global scope, the following works

window[ myObj.id ].data

If you are in a function's scope, things get a lot harder. Easiest way then is to define your objects in a specific namespace on window and retrieve the objects similar to the above code.

回答2:

Store test1 and test2 in a key-value collection (aka an object.) Then access it like:

collection[myObj.id].data

回答3:

If you want to refer to something using a variable, then make that something an object property, not a variable. If they are sufficiently related to be accessed in that way, then they are sufficiently related to have a proper data structure to express that relationship.

var data = {
    test1: {
        id: "test1",
        data: "Test 1 test 1 test 1"
    },
    test2: {
        id: "test2",
        data: "Test 2 test 2 test 2"
    }
};

Then you can access:

alert( data[myObj.id] );

回答4:

Great answers all, thanks for the help, in case any one finds this in future, this is how I'm going to use it:

var parent = {}

parent.test1 = {
    id : "test1",
    data : "Test 1 test 1 test 1"
}

parent.test2 = {
    id : "test2",
    data : "Test 2 test 2 test 2"
}


var myObj = null;

function setMyObj(obj){
   myObj = obj;
}


setMyObj(parent.test1);

parent[myObj.id] = null;
//Test1 object is now null, not myObj!

来源：https://stackoverflow.com/questions/11102611/javascript-use-string-as-object-reference

标签

javascript

javascript-objects