Link two strings within the same object

Question

   var object={
      firstString: 'You must register in order...',
      secondString:'You must re-enter your password in order to...',
      thirdString:'You must re-enter your password in order to...'
    };

As you see second and third string are the same. Because this happens multiple times in the object I am using right now I want to link third object with the second one in order to save some bytes

I have tried the following but they don't work

var object={
  firstString:'You must register in order...',
  secondString:'You must re-enter your password in order to...',
  thirdString:this.secondString
};

var object={
      firstString:'You must register in order...',
      secondString:'You must re-enter your password in order to...',
      thirdString:object.secondString
};

Thank you

Syntax error: `firstString='You must register in order...'` should be `firstString`**:** `'You must register in order...'` — Kevin Boucher, Aug 29 '13 at 19:51

score 7 · Accepted Answer · answered Aug 29 '13 at 19:50

You can't construct self-referential expressions inside an object literal. You have to follow up the declaration initialization with another statement.

var object={
  firstString='You must register in order...',
  secondString:'You must re-enter your password in order to...',
};
object.thirdString = object.secondString;

If you really want to initialize the variable in a single expression, you can use a function:

var object = function() {
  var o = {
    firstString='You must register in order...',
    secondString:'You must re-enter your password in order to...',
  };
  o.thirdString = o.secondString;
  return o;
}();

Note that it's not impossible that modern JavaScript VM innards notice duplicated string constants in some circumstances, and optimize away the redundancy. I don't know one way or the other whether they do.

score 4 · Answer 2 · answered Aug 29 '13 at 19:52

You can't do that the way you are trying to. Objects literals are not complete until you finish them, and they can't be referneced before they complete. You have set the string to a variable, and then use that variable.

var prompt = 'You must re-enter your password in order to...';
var obj = {
  msg1: prompt,
  msg2: prompt,
  otherMessage: 'Some string'
};

score 1 · Answer 3 · answered Aug 29 '13 at 19:55

1

The easiest way would be to define what the string you are referring to is. eg. string passwordAsk = 'You must re-enter your password in order to...'. This will also allow you to more easily change all of them in the future.

answered Aug 29 '13 at 19:55

ford prefect

7,096
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score 1 · Answer 4 · edited Jun 20 '20 at 09:12

To expand off Pointy's answer:

You can try and do this:

var Obj = (function () {
    
    function Obj() {
        this.obj = {};
    }

    Obj.prototype.set = function(name, value) {
         this.obj[name] = value;
    };

    return Obj;
})();

var object = new Obj();
object.set('firstString', 'You must register in order...');
object.set('secondString', 'You must re-enter your password in order to...');
object.set('thirdString', object.obj.secondString);

Then you can use object.obj as the object.

You can create multiple Obj objects that you can use in the same fashion.

Or

Instead of using some convoluted Obj class you can just do:

var object = {};
object.firstString = 'You must register in order...';
object.secondString = 'You must re-enter your password in order to...';
object.thirdString = object.secondString;

score 1 · Answer 5 · answered Aug 29 '13 at 20:04

Or if you want to have fun you can try it this way (disclaimer: I wouldn't do this, but I enjoyed the challenge)

function selfReferencer(generator) {
    var temp = generator.apply({});
    return generator.apply(temp);
}

and then build your objects like this:

var obj = selfReferencer(function() { return {
    firstString: 'You must register in order...',
    secondString: 'You must re-enter your password in order to...',
    thirdString: this.secondString
}});

No love? Not even a downvote? :p – InvisibleBacon Aug 29 '13 at 20:18 — InvisibleBacon, Aug 29 '13 at 20:18

Link two strings within the same object

5 Answers5

Or