optional parameter

[jeorg]

I have this function
---------------------------------------------------

function BuildIcone(mImg, mClass)
{
if (mClass !="")
{
return "<img src='" + mImg + ".gif' class='" + mClass + "' alt='' />";
}
else
{
return "<img src='" + mImg + ".gif' class='imgMenuG' alt='' />";
}
}

-----------------------------------------------
I can call it in that way
BuildIcone("car","imgMenuG")

but I want an optional parameter

then if I do

BuildIcone("car")

the second value must be imgMenuG

and it doesn't work

why ?

thank you

[Garadon]

Cant Remember if Java script supports this but try this.

function BuildIcone(mImg, mClass)
{
return "<img src='" + mImg + ".gif' class='" + mClass + "' alt='' />";
}

function BuildIcone(mImg)
{
return "<img src='" + mImg + ".gif' class='imgMenuG' alt='' />";
}

[x_goose_x]

instead of using:

BuildIcone("car");

use:

BuildIcone("car","");

[x_goose_x]

the two functions like Garadon suggested would cause an error.

you might also want to try using:

if (mClass.length >= 1)

[jeorg]

but you are really obliged to do "car",""
you cannot have optional parameter in javascript ?

and if is emptyor null you return the optional value

Like Garadon it works in VB net and it is very practicle, to avoid empty optional parameters

[glenngv]

function BuildIcone(mImg, mClass)
{
if (mClass !="" && mClass!=null && typeof mClass!="undefined")
{
return "<img src='" + mImg + ".gif' class='" + mClass + "' alt='' />";
}
else
{
return "<img src='" + mImg + ".gif' class='imgMenuG' alt='' />";
}
}


these will all produce the same result:

BuildIcone("car","imgMenuG");
BuildIcone("car");
BuildIcone("car","");
BuildIcone("car",null)

[jeorg]

thank you very much

[glenngv]

welcome. :)
actually, you can optimize the code like this:

function BuildIcone(mImg, mClass)
{
mClass = (mClass !="" && mClass!=null && typeof mClass!="undefined") ? mClass:'imgMenuG';
return "<img src='" + mImg + ".gif' class='" + mClass + "' alt='' />";
}