I have an object parameter and it has a property value. it is thusly defined

var parameter = {
    value : function() {
        //do stuff
    }
};

my problem is that, in some cases, value needs to have a property of its own named length

can i do that? it seems that putting this.length = foo does not work, neither does parameter.value.length = foo after the object declaration.

I have an object parameter and it has a property value. it is thusly defined

var parameter = {
    value : function() {
        //do stuff
    }
};

my problem is that, in some cases, value needs to have a property of its own named length

can i do that? it seems that putting this.length = foo does not work, neither does parameter.value.length = foo after the object declaration.

• javascript
• properties

• Do you mean that the returned object from value() needs to have a length? – Hemlock Commented Jan 25, 2011 at 17:22
• no, i check value's length and iterate over it as though it were an array. – griotspeak Commented Jan 25, 2011 at 17:37

3 Answers 3

The problem seems to be with the selection of the word 'length'. In JavaScript, functions are objects and can have properties. All functions already have a length property which returns the number of parameters the function is declared with. This code works:

var parameter = {
    value : function() {
        //do stuff
    }
};

parameter.value.otherLength = 3;

alert(parameter.value.otherLength);

parameter.value.length should work. Run the following:

var obj = {
    method: function () {}
};
obj.method.foo = 'hello world';
alert(obj.method.foo); // alerts "hellow world"

Functions are technically objects, so they can have methods and properties of their own.

Try this. It should work:

var parameter = {
  value : {
    length : ''
  }
}

var newLength = parameter.value.length = 10;
alert( newLength ); // output: 10

If I understand your question, basically, in object literals notation, an object can contain another object and so on. So to access the inner object and its properties, you just have to do the dot natation as usual following the hierarchy. In the above case 'parameter' then the inner-object, 'value', then the inner-object property, 'length'.