Convertion from bytes 8,16,32 to String

Question

I know it has been asked a lot of times but the newest post about this I could find was about 1 year old. To me it seems quite possible that things have changed since then. So my question: Is there an easy way to convert bytes8/16/32 to a String value?

Here is the problem I face right now. Contract A takes one user-input per transaction as a bytes8/16/32 variable. The contract passes it to Contract B and stores it there. My getter function in Contract B returns this Bytes8/16/32 variable. So Contract A calls the getter-function of B if needed and successfully gets the bytes variable back. Now I simply want to turn it back to a readable string and put it on screen in a decoded way :) Somebody has an idea? Many thanks!

Answer 1

I'm assuming you're invoking your Ethereum contract from JavaScript. If that's the case, you probably need web3.toAscii()

var str = web3.toAscii("0x657468657265756d000000000000000000000000000000000000000000000000");
console.log(str); // "ethereum"

Answer 2

If your need for a readable string is just for the Web interface and you are using web3.js you can use :

var str = web3.toUtf8("0x657468657265756d000000000000000000000000000000000000000000000000");
console.log(str); // "ethereum"

web3.toAscii can still return some not desirable characters, and since UTF-8 is most used, i suggest the web3.toUtf8

An other way is to try and parse the bytes32 to a readable string inside your contract. to do so please refer to this question it has the best answer.

How to convert a bytes32 to string