如何读取对象文字的JavaScript数组？

Question

In a JavaScript application that I am working on I have an array of objects:

function Message(title, message) {
    this.title=title;
    this.message=message;
}

var MessageArray = new Array();
MessageArray[0] = new Message("Some Title", "Some new message.");

I have an issue that I need to debug. Is there any way to read or sniff the current objects in the array, including their title and message properties? I could add another function to alert() me with those values, but if there is a tool that I could use much like the Visual Studio debugger then I would love to know about it. I took a look at Firebug but it does not seem to have this capacity.

To be clear, I am looking for a debugger that will let me inspect any variable at runtime, not specifically MessageArray at the moment. I did find Chrome's Scope Variables pane, but it seems to only list scalars, not arrays!

Answer 1

Most modern browsers have a built in developers console with all the functionality of a normal debugger. Breakpoints and variable inspecting ect. In chrome you can open it through the tools menu or by pressing f12.

You can also use the JavaScript Console.log(); to log anything you want to the developer console. This stop you using alerts which stop JavaScript executing while the alert it up.

In the case console.log(MessageArray[0].title, MessageArray[0].message); would print out the title and the message to the console.

EDIT:

Here is a screen shot of the console inside chrome. Showing me create your objects and then interacting with them via the console.

Answer 2

All modern browsers ( IE 7+, Firefox, Chrome, Opera ) have debug (developer) console, so try use it as classic debugger

IE debug console is too from Microsoft, so try to use it - and Firebug CAN do this ( try wath MessageArray - you will find it all there )

Answer 3

You can refer to those properties, for example, like this:

MessageArray[0].title    
MessageArray[0].message

Answer 4

Firebug's debugger has the functionality you need. just take a good look at it. if you mean using IDE tool, I'm not aware of such.

Answer 5

In your case you can read title and message of the stored Message object like that:

var title = MessageArray[0].title;
var message = MessageArray[0].message;

To get title and message of each object within array, just do:

for (var i=0; i<MessageArray.length; i++){
    // here MessageArray[i].title is the current title
    // here MessageArray[i].message is the current message
}