convert object to string

[Max]

I just wonder if there is a way of converting an object to a string.
I am using a function to send an object parameter e.g "fctng(train0); "
later on I would like to use train0 but as a string to access a
img id called <img id="train0"> .
This might be obvious to you but I am not a programmer, just trying to
learn javascript at home for fun.
Thanks

Max

[web.dev]

Re: convert object to string

Hi Max,
[color=blue][color=green]
>> I just wonder if there is a way of converting an object to a string.[/color][/color]

Yes and no. It depends on the situation. Are you wanting to convert a
javascript object or a user-defined object? All javascript objects
have a toString method, however if it's an object that you've made
yourself, you'll need to provide a way to convert it to a string.

[Richard Cornford]

Re: convert object to string

Max wrote:[color=blue]
> I just wonder if there is a way of converting an object
> to a string.[/color]

In loosely typed javascript any type can be converted into any other
type, and they are automatically internally converted to resolve
expressions whenever the context of use requires a different type. See:-

<URL: http://www.jibbering.com/faq/faq_not...e_convert.html >


The rule for converting Objects to strings is that the object's -
toString - method is called and the result is the string primitive value
of the object. Objects inherit default - toString - methods from their
prototype. For objects created with the object constructor, constructor
functions and object literals that - toString - function is the one
defined on the - Object.prototyp e -, which is not particularly useful as
it is specified as returning "[object Object]".

You get around the default - toString - methods of objects by providing
your own. EG:-

function MyObject(type, value){
this.type = type;
this.value = value;
}
MyObject.protot ype.toString = function(){
return (
"[MyObject: \n\ttype = "+
this.type+
"\n\tvalue = "+
this.value+
"\n]\n"
);
};

- giving an object that when type-converted to a string (or as a result
of having its toString method called directly) will return a string
describing the object's current state. I.E.:-

var obj = new MyObject('somet ype', 55);

var str = ''+obj; //concatenation forces obj's type-conversion to a
string.

alert(str); // --> outputs:-

[MyObject:
type = sometype
value = 55
]

- in the alert box.

The same result will follow from calling the object's - toString -
method directly as:-

obj.toString();
[color=blue]
> I am using a function to send an object parameter e.g
> "fctng(train0); " later on I would like to use train0 but
> as a string to access a img id called <img id="train0"> .[/color]

That is not a sufficient explanation of what you are attempting (or why)
to convey meaning. Remember, code always contributes to understanding
when you are talking about scripting.
[color=blue]
> This might be obvious to you but I am not a programmer,
> just trying to learn javascript at home for fun.[/color]

No harm in that. Look at the information that the FAQ provides on the
subject of asking questions, it will help in the long run.

Richard.