访问同一功能内的其他功能

Question

there is some way to do this?

 function test()
    {

        this.write = function(text)
        {
            alert(text);
        }

        this.read = function()
        {
            this.write('foo');
            // WRONG WAY
            // test.write('foo');
        }
    }

How can i call the "this.write" function from "this.read"?

EDIT:

Found the awnser by EricG. Have tried with the code above and it works. But my real code still not working. I've to figure out what's happening.

The Way to call "THIS.WRITE" from inside "THIS.READ" is just by calling 'this.write()". Just like that.

Thanks!

Answer 1

function test()
{
    this.write = function(text)
    {
        alert(text);
    }

    this.read = function()
    {
        this.write('foo');
    }
}

var a = new test();
a.read();

jsFiddle

Answer 2

Try this:

function test()
{

    this.write = function(text)
    {
        alert(text);
    }

    this.read = function()
    {
        this.write('foo');
    }
}

var t = new test();
t.read();

fiddle

Answer 3

function test()
{
   var self = this;

    this.write = function(text)
    {
        alert(text);
    };

    this.read = function()
    {
        self.write('foo');
    };

    // depending on browser versions or included libraries.
    this.another = function () {
        this.write('foo');
    }.bind(this);
}

You can also use this without the bind call, but under certain circumstances the meaning of 'this' may change.

Answer 4

That totally depends on, where the function is called from. I would suggest reading some more about the this keyword Maybe take a look at this SO question

If you create an Instance of test

function test()
{

    this.write = function(text)
    {
        alert(text);
    }

    this.read = function()
    {
        this.write('foo');
    }
}
var inst = new test()
inst.read() //foo
inst.read.call() //Uncaught TypeError: Object [object Window] has no method 'write'

And call the method read of this instance, this will refer to the well ,this instance of test

However if your code doesn't work, the method is probably called with another context. Maybe an Eventlistener you added. And the callback function of it tries to call this.write
then this wouldn't refer anymore to the instance of test/your function.

What you could also do is preserving the context in a local variable like

function test()
{
    var context = this;
    this.write = function(text)
    {
        alert(text);
    }

    this.read = function()
    {
        context.write('foo');
    }
}
var inst = new test()
inst.read() // foo
inst.read.call() //foo 

So as you see in the second case the write gets executed although read is called with the Global Object Window as its context.

Heres a JSBin