Associative with MultiDimensional arrays

A

Aziz

Hi,

I'm trying to mix them up for something like this but firefox gives me
profiles.p1 is undefined error...

<html><body>

<script type="text\javascript">
function showVal()
{
alert(profiles["p1"][0].x);
}

function profileRecord(x, y, z)
{
this.x = x;
this.y = y;
this.z = z;
}

var profiles = new Array(3);

profiles["p1"][0] = new profileRecord(10, 20, 30);
profiles["p1"][1] = new profileRecord(10, 20, 30);
profiles["p1"][2] = new profileRecord(10, 20, 30);
</script>

<form>
<input type="button" onclick="showVal()" value="Show" />
</form>

</body></html>

I expect "10" would be displayed but instead I get the error that
profiles.p1 doesn't exist. How can I correct it?

Thanks
 
V

VK

Aziz said:
profiles["p1"][0] = new profileRecord(10, 20, 30);
profiles["p1"][1] = new profileRecord(10, 20, 30);
profiles["p1"][2] = new profileRecord(10, 20, 30);
Click to expand...
alert(profiles["p1"][0].x);
Click to expand...

is effectively
undefined[0] = new profileRecord(10, 20, 30);
alert(undefined[0].x)
this makes the problem more visual.
I expect "10" would be displayed but instead I get the error that
profiles.p1 doesn't exist. How can I correct it?
Click to expand...

function showVal()
{
alert(profiles[1].x);
}

function profileRecord(x, y, z)
{
this.x = x;
this.y = y;
this.z = z;
}

var profiles = new Array(3);

profiles[0] = new profileRecord(10, 20, 30);
profiles[1] = new profileRecord(10, 20, 30);
profiles[2] = new profileRecord(10, 20, 30);
 
A

Aziz

Aziz said:
profiles["p1"][0] = new profileRecord(10, 20, 30);
profiles["p1"][1] = new profileRecord(10, 20, 30);
profiles["p1"][2] = new profileRecord(10, 20, 30);
Click to expand...
alert(profiles["p1"][0].x);
Click to expand...

is effectively
undefined[0] = new profileRecord(10, 20, 30);
alert(undefined[0].x)
this makes the problem more visual.
I expect "10" would be displayed but instead I get the error that
profiles.p1 doesn't exist. How can I correct it?
Click to expand...

function showVal()
{
alert(profiles[1].x);
}

function profileRecord(x, y, z)
{
this.x = x;
this.y = y;
this.z = z;
}

var profiles = new Array(3);

profiles[0] = new profileRecord(10, 20, 30);
profiles[1] = new profileRecord(10, 20, 30);
profiles[2] = new profileRecord(10, 20, 30);
Click to expand...

Thanks but what you suggest is a 2 dimensional array, while I try to
implement a 3 dimensional array with the first index as a string. Is
it not possible?
 
V

VK

Aziz said:
I try to implement a 3 dimensional array with the first index as a string. Is
it not possible?
Click to expand...

Definitely not, because there are not "arrays with string index", they
do not exist in the nature. There objects of type Object with
properties and objects of type Array with integer indicies.

You can create an object and store array references as its properties:

var obj = {};

obj.p1 = [1,2,3];
obj.p2 = [1,2,3];

further more each array element can hold a reference either to a map or
an array:

obj.p1[0] = [1,2,3];
obj.p2[1] = {'foo':'bar'};

and further and further up to structures of any complexity.
 
R

RobG

Aziz said:
Hi,

I'm trying to mix them up for something like this but firefox gives me
profiles.p1 is undefined error...

<html><body>

<script type="text\javascript">
function showVal()
{
alert(profiles["p1"][0].x);
}

function profileRecord(x, y, z)
{
this.x = x;
this.y = y;
this.z = z;
}

var profiles = new Array(3);

profiles["p1"][0] = new profileRecord(10, 20, 30);
Click to expand...

profiles["p1"] = [ new profileRecord(10, 20, 30) ];
profiles["p2"] = [ new profileRecord(10, 20, 30) ];
...
profiles["p1"][1] = new profileRecord(10, 20, 30);
profiles["p1"][2] = new profileRecord(10, 20, 30);
</script>

<form>
<input type="button" onclick="showVal()" value="Show" />
</form>

</body></html>

I expect "10" would be displayed but instead I get the error that
profiles.p1 doesn't exist. How can I correct it?
Click to expand...

Do you intend to use any of profiles' array-ness? You appear to be
using it as a simple object, so:

profiles = new Object();
profiles["p1"] = [ new profileRecord(10, 20, 30) ];
profiles["p2"] = [ new profileRecord(10, 20, 30) ];
profiles["p3"] = [ new profileRecord(10, 20, 30) ];

or

profiles = {
p1 : [ new profileRecord(10, 20, 30) ],
p2 : [ new profileRecord(10, 20, 30) ],
p3 : [ new profileRecord(10, 20, 30) ]
}


Would be considered more approrpriate. I wouldn't call it a
multi-dimensional array, it's just a collection of named arrays that
each has a single element: an object with properties x, y and z.

A multi-dimensional array would have the property names as indexes of
an array:

profiles = [
[ new profileRecord(10, 20, 30) ],
[ new profileRecord(10, 20, 30) ],
[ new profileRecord(10, 20, 30) ]
]


Your profileRecord objects are just plain objects, you could also
create them using:

profiles = {
p1 : [ {x:10, y:20, z:30} ],
p2 : [ {x:10, y:20, z:30} ],
p3 : [ {x:10, y:20, z:30} ]
}
 
A

Aziz

Thanks a lot...


Hi,

I'm trying to mix them up for something like this but firefox gives me
profiles.p1 is undefined error...

<html><body>

<script type="text\javascript">
function showVal()
{
alert(profiles["p1"][0].x);
}

function profileRecord(x, y, z)
{
this.x = x;
this.y = y;
this.z = z;
}

var profiles = new Array(3);

profiles["p1"][0] = new profileRecord(10, 20, 30);
Click to expand...

profiles["p1"] = [ new profileRecord(10, 20, 30) ];
profiles["p2"] = [ new profileRecord(10, 20, 30) ];
...
profiles["p1"][1] = new profileRecord(10, 20, 30);
profiles["p1"][2] = new profileRecord(10, 20, 30);
</script>

<form>
<input type="button" onclick="showVal()" value="Show" />
</form>

</body></html>

I expect "10" would be displayed but instead I get the error that
profiles.p1 doesn't exist. How can I correct it?
Click to expand...

Do you intend to use any of profiles' array-ness? You appear to be
using it as a simple object, so:

profiles = new Object();
profiles["p1"] = [ new profileRecord(10, 20, 30) ];
profiles["p2"] = [ new profileRecord(10, 20, 30) ];
profiles["p3"] = [ new profileRecord(10, 20, 30) ];

or

profiles = {
p1 : [ new profileRecord(10, 20, 30) ],
p2 : [ new profileRecord(10, 20, 30) ],
p3 : [ new profileRecord(10, 20, 30) ]
}


Would be considered more approrpriate. I wouldn't call it a
multi-dimensional array, it's just a collection of named arrays that
each has a single element: an object with properties x, y and z.

A multi-dimensional array would have the property names as indexes of
an array:

profiles = [
[ new profileRecord(10, 20, 30) ],
[ new profileRecord(10, 20, 30) ],
[ new profileRecord(10, 20, 30) ]
]


Your profileRecord objects are just plain objects, you could also
create them using:

profiles = {
p1 : [ {x:10, y:20, z:30} ],
p2 : [ {x:10, y:20, z:30} ],
p3 : [ {x:10, y:20, z:30} ]
}
Click to expand...
 
A

Aziz

Thanks a lot...

I try to implement a 3 dimensional array with the first index as a string. Is
it not possible?
Click to expand...

Definitely not, because there are not "arrays with string index", they
do not exist in the nature. There objects of type Object with
properties and objects of type Array with integer indicies.

You can create an object and store array references as its properties:

var obj = {};

obj.p1 = [1,2,3];
obj.p2 = [1,2,3];

further more each array element can hold a reference either to a map or
an array:

obj.p1[0] = [1,2,3];
obj.p2[1] = {'foo':'bar'};

and further and further up to structures of any complexity.
Click to expand...
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Similar Threads

Issue with key down - JS 3
Having an issue with empty arrays 2
SENTINEL CONTROL LOOP WHEN DEALING WITH TWO ARRAYS 1
Help with code 0
Graph of quadratic function with CanvasRenderingContext2D 2
Help with my responsive home page 2
Problem with codewars. 5
I Need Help with making a function that draws in a canvas using location data. 1

Members online

No members online now.
Total: 29 (members: 0, guests: 29)
Robots: 318

Forum statistics

Threads
473,995
Messages
2,570,236
Members
46,825
Latest member
VernonQuy6

Latest Threads

Top