How to solve this minimal js code issue?

My inputs are: an array of object names and objects. I want to loop through the array for object name and then output something from corresponding object. My code is as follows:

    options=["bold","italic"] ;

    var bold ={
            action: function(){
                alert("<strong>just bold</strong>");
            },
            b_p: "-40px bold"
     };

    var italic ={
            action: function(){
                alert("<em>an italic</em>");
            },
            b_p: "-20px italic"
     };

     for(i=0;i<options.length;++i)
     {
         document.write(options[i].b_p);
     }

My 开发者_运维技巧desired output: "-40px bold -20px italic" but I get an error saying: "undefined undefined".

Please help me to find out my mistake/ignorance here.

Thanks.

/******/ Update: the problem is solved below :-) Thanks communtiy

Instead of passing the names, pass an object array:

var bold = {
            action: function(){
                alert("<strong>just bold</strong>");
            },
            b_p: "-40px bold"
};

var italic = {
            action: function(){
                alert("<em>an italic</em>");
            },
            b_p: "-20px italic"
};

var options = [ bold, italic ]; // symbols, not strings

for(var i=0;i<options.length;++i)
{
         document.write(options[i].b_p);
}

Nothing else would really need to change.

A few problems here:

options=["bold","italic"] ; should be options=[bold,italic];

and should be after the declaration of the bold and italic vars

Also, for(i=0;i<options.length;++i) should be for(i=0;i<options.length;i++) (note the post-increment instead of a pre-increment)

So to sum it up:

var bold ={
        action: function(){
            alert("<strong>just bold</strong>");
        },
        b_p: "-40px bold"
 };

var italic ={
        action: function(){
            alert("<em>an italic</em>");
        },
        b_p: "-20px italic"
 };

 var options=[bold,italic];

 for(i=0;i<options.length;i++)
 {
     document.write(options[i].b_p);
 }

Here is a much more cleaner approach:

var options = {
    "bold": {
        "action": "<strong>just bold</strong>",
        "b_p": "-40px bold"
    },

    "italic": {
        "action": "<em>an italic</em>",
        "b_p": "-20px italic"
    }
};

for (var i in options) {
    document.write(options[i]["b_p"] + "<br />")
}

Example: http://jsfiddle.net/sea2d/

If you wanted to alert your action, you could just use:

alert(options["bold"]["action"]);