Prototype issue

[akiva_atwood]

I'm playing with adding FP functionality -- but prototype isn't working for me.

A code sample - I get an "a.indexOf is not a function" error. Anyone see why I'm getting that error? It works fine in a javascript editor.

main();

function main(){

var a=[4,9,16];

alert(a);

b=a.indexOf(9);

alert(b);

}

Array.prototype.indexOf = function (elem, fromIndex){

    fromIndex = Number(fromIndex) || 0;

    var len = this.length;

    if (fromIndex < 0){

        fromIndex += len;

    }

    for(var i=fromIndex;i<this.length;i++){

        if(this == elem){

            return i;

        }

    }

    return -1;

}

[Laubender · Accepted solution]

Hi,

declare your prototype inside of main() before using it.

This is working:

main();
function main()
{
    Array.prototype.indexOf = function (elem, fromIndex)
    {
        fromIndex = Number(fromIndex) || 0;
        var len = this.length;
        if (fromIndex < 0)
        {
            fromIndex += len;
        }
        for(var i=fromIndex;i<this.length;i++)
        {
            if(this == elem)
            {
                return i;
            }
        }
        return -1;
    };
    var a=[4,9,16];
    alert(a);
    b=a.indexOf(9);
    alert(b);
};

Or declare your prototype before everything else:

Array.prototype.indexOf = function (elem, fromIndex)
{
    fromIndex = Number(fromIndex) || 0;
    var len = this.length;
    if (fromIndex < 0)
    {
        fromIndex += len;
    }
    for(var i=fromIndex;i<this.length;i++)
    {
        if(this == elem)
        {
            return i;
        }
    }
    return -1;
};
main();
function main()
{
    var a=[4,9,16];
    alert(a);
    b=a.indexOf(9);
    alert(b);
};

But e.g. this is not working:

main();
function main()
{
    var a=[4,9,16];
    alert(a);
    b=a.indexOf(9);
    alert(b);
    Array.prototype.indexOf = function (elem, fromIndex)
    {
        fromIndex = Number(fromIndex) || 0;
        var len = this.length;
        if (fromIndex < 0)
        {
            fromIndex += len;
        }
        for(var i=fromIndex;i<this.length;i++)
        {
            if(this == elem)
            {
                return i;
            }
        }
        return -1;
    };
};

ExtendScript is a bit picky on prototype.

BTW: You can use the forum's Advanced Editing feature to format your text as code.

>> Insert > Syntax Highlighting > javascript

Regards,
Uwe

[akiva_atwood]

Thanks. I figured scope would take care of that...