# DApp Development

Currently, DEXON uses Ethereum's virtual machine (EVM) as the default VM. So Dapp development on DEXON is exactly the same as on Ethereum. An exception is that if you want to use DEXON's [on-chain random oracle](https://github.com/dexon-foundation/wiki/wiki/On-Chain-Random-Oracle).

DEXON's fork of solidity (called [dsolidity](https://github.com/dexon-foundation/dsolidity)) supports a special built-in variable called `rand`. Here is an example of how to use it:

```
contract Rand {
    uint256 value;

    function update() public {
        value = rand;
    }

    function get() view public returns (uint256) {
        return value;
    }
}
```

This very simple contract demonstrates how to use the `rand` variable. When `update()` is called, the state `value` is assigned to a random value generated by DEXON's on-chain random oracle.

The most simple way to develop Dapps on DEXON is to use the DEXON version of the Remix IDE: https://remix.dexon.org. You should use this with the DekuSan Web Wallet([Chrome](https://chrome.google.com/webstore/detail/dekusan/anlicggbddjeebblaidciapponbpegoj)/[Firefox](https://addons.mozilla.org/en-US/firefox/addon/dekusan)). To get free testnet token, please check the [faucet](https://dexon.org/faucet).

If you are developing apps with truffle, you will need to use [dsolidity](https://github.com/dexon-foundation/dsolidity). The nodejs version can also be found [here](https://github.com/dexon-foundation/dsolc-js).

### Truffle

[Truffle](https://github.com/trufflesuite/truffle) is a set of tools for developing solidity apps, originally developed by ConsenSys.  
The [DEXON-port of Truffle](https://github.com/dexon-foundation/truffle) uses dsolidity, which supports on-chain unbiased randomness.

Get the DEXON-port of truffle suite from `npm install -g @dexon-foundation/truffle`  
You can check out our demo DApp [hello-dexon](https://github.com/dexon-foundation/hello-dexon) and learn how to compile, test and deploy your smart contracts.

1. `mkdir hello-dexon && cd hello-dexon`
2. `dexon-truffle unbox dexon-foundation/hello-dexon`
3. Use `dexon-truffle compile` to compile the final byte-code
4. Deploy onto the DEXON network by `dexon-truffle migrate --network=testnet`

### Ganache

[Ganache](https://github.com/trufflesuite/ganache) is a JavaScript mock of Ethereum blockchain, for developing and testing smart contracts and other blockchain operations.  
The [DEXON version of Ganache](https://github.com/dexon-foundation/ganache-cli) adds additional op-codes that DEXON blocklattice introduced.

```
> npm i -g @dexon-foundation/ganache-cli
> dexon-ganache
```