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IndexOf problem

Posted: November 2nd, 2009, 12:20 pm
by ghaith
hi all
i know i have many questions but for now the most important is how to use String.indexOf()

i don't know why it is not working for me any idea .


thank you :shock:

Re: IndexOf problem

Posted: November 2nd, 2009, 1:35 pm
by lloydalvarez

Code: Select all

var str = "my string";

str.indexOf("m");    //result:  0
str.indexOf("s");    //result:  3
str.indexOf("t");    //result:  4

Re: IndexOf problem

Posted: November 16th, 2009, 5:24 am
by laracroft
Hi Ghaith. I am Lara.

Lloydalvarez's code is working. You should try this.

Have a nice day.

Re: IndexOf problem

Posted: May 4th, 2014, 1:49 am
by luigihmtz
Hello, everyone.

It turns out that the indexOf method works fine with strings, but it fails when used with arrays, as opposed to regular javascript, which supports either.

For instance, this expression would cause an error in AE, as it shows Undefined because the variable contains an array. If you try this e.g. on "web" javascript, it won't break:

Code: Select all

fruits = ["Banana", "Orange", "Apple", "Mango"];
a = fruits.indexOf("Apple"); 
But this one will always work because the variable contains a string, not an array:

Code: Select all

numbers = "95? 10, 034";
a = numbers.indexOf("5"); 
So how can I retrieve an index number from some whole element (not an individual character) that is part of an array of strings by typing its full string? Just like my fruits example above.

BTW I'm using AECC. Cheers.

Re: IndexOf problem

Posted: May 4th, 2014, 8:18 am
by lloydalvarez
luigihmtz wrote: It turns out that the indexOf method works fine with strings, but it fails when used with arrays, as opposed to regular javascript, which supports either.
IndexOf is a string function and doesn't work with arrays anywhere. To get an item in an array by index you simply do this:

Code: Select all

myArray[3]; //gets the third item in the array
http://www.w3schools.com/js/js_obj_array.asp

Re: IndexOf problem

Posted: May 5th, 2014, 1:35 pm
by luigihmtz

IndexOf is a string function and doesn't work with arrays anywhere.
Sorry, my bad, I mixed up stuff.

I do know that indexOf has a string-only input parameter but, at least in regular javascript, it is NOT a string-only method. What I mean is that you can use either an array of strings or a mere string interchangeably along with indexOf.

That said, my setback remains true: After Effects appears to be capable of handling strings only, not arrays, regarding the thing whom indexOf is applied to. I also acknowledge that you can call any element by its index, but I need to do the opposite (hence the use of the indexOf), I mean, by bringing in a given string element I'll get its corresponding index number, which is the output i need.

I'm still trying to figure this out, but thanks for such a quick answer. :o

Re: IndexOf problem

Posted: May 5th, 2014, 1:37 pm
by luigihmtz
luigihmtz wrote:

IndexOf is a string function and doesn't work with arrays anywhere.
Sorry, my bad, I mixed up stuff.

I do know that indexOf has a string-only input parameter but, at least in regular javascript, it is NOT a string-only method. What I mean is that you can use either an array of strings or a mere string interchangeably along with indexOf.

That said, my setback remains true: After Effects appears to be capable of handling strings only, not arrays, regarding the thing whom indexOf is applied to. I also acknowledge that you can call any element by its index, but I want to do the opposite (hence the use of the indexOf), I mean, by bringing in a given string element I'll get its corresponding index number, which is the output i need.

I'm still trying to figure this out, but thanks for such a quick answer. :o

Re: IndexOf problem

Posted: May 5th, 2014, 2:44 pm
by lloydalvarez
After Effects scripting is "regular" javascript. They are only different in the extended methods. All the base Javascript is exactly the same, i think you are misunderstanding strings and arrays.

Re: IndexOf problem

Posted: May 5th, 2014, 3:15 pm
by luigihmtz
Hopefully this should make my point clearer:
For instance, this expression would cause an error in AE, as it shows Undefined because the variable contains an array. If you try this e.g. on "web" javascript, it won't break:

Code: Select all

fruits = ["Banana", "Orange", "Apple", "Mango"];
a = fruits.indexOf("Apple"); 
But this one will always work because the variable contains a string, not an array:

Code: Select all

numbers = "95? 10, 034";
a = numbers.indexOf("5"); 
Thanks!

Re: IndexOf problem

Posted: May 5th, 2014, 4:12 pm
by luigihmtz
OK, I came out with this:

Code: Select all

feed = "Banana";
fruits = [ ];
fruits[0] = "Banana";
fruits[1] = "Orange";
fruits[2] = "Apple";
fruits[3] = "Mango";

for (var i=0; i<fruits.length; i++)
  {
	if ( feed == fruits[i] ){
	  idx = i;
	  break;
	} else { 0 }
}
Not quite elegant, but it works.

Re: IndexOf problem

Posted: May 6th, 2014, 2:06 pm
by beginUndoGroup
ExtendScript implements ECMA Standard 262 3rd Edition (December 1999), while the latest 'official' edition is the 5th (June 2011).
There are now plenty of new methods for arrays, like indexOf, every, forEach, map, filter, reduce, some...
But ExtendScript doesnt have them.

You can do something like this:

Code: Select all

function myIndexOf(array, x){
	var n=-1, N=array.length;
	while (++n<N && array[n]!==x);
	return n<N ? n : -1;
	};

Re: IndexOf problem

Posted: June 4th, 2021, 6:39 am
by devengineer
lloydalvarez wrote:
May 5th, 2014, 2:44 pm

After Effects scripting is "regular" javascript. They are only different in the extended methods. All the base Javascript is exactly the same, i think you are misunderstanding strings and arrays.

Yes, that's said correctly. In addition, there is opposite function, which is lastIndexOf(), you can use it if you need to search something in a backward direction.

You may look into it in official Mozilla's guide or here: https://aneze.com/check-if-a-string-con ... javascript