Convert any audio format file to mp3?

You going to have to use a 3rd party tool.

Every format is different and you're going to have to write code to parse every format you want to support. You can't just say "any format". There are going to be limitations to what you're going to be able to support if you don't want to spend the rest of your life writing code to parse every format.

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Is there any Possibility to convert any format of audio file(including wma,wav,aac,ogg) to mp3 ?

Yes, you just need a decoder for every format you want to convert.

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i need built in functionality, i don't want to use third party tools.

Then you will have to pay engineers for years to rebuild all the decoders.
Note that everything you use is third party tool: OS (windows, Linux, android...), web browser (Chrome, Firefox), compilers ...