Solidity – How to Convert Hex Numbers Using JavaScript?

If your token have 18 decimals

like an ether you can use

then(function(balance) {
    console.log(web3.fromWei(balance.toNumber(), "ether" ) );
})

Use fromWei to convert your bigNumber to ether and then convert it to Number. Be aware that unnecessary 0 after the floating point will not be displayed.

In web3 ^1.0 it may change to web3.utils.fromWei instead of web3.fromWei doc. Note that truffle ^5.0 uses web3 ^1.0.

If you have a different token decimal

Let's say 6. You'll have to do the conversion manually with something like:

var tokenBalance = balance.ToNumber() / Math.pow(10, tokenDecimals)

Try this:

let EVENT = [
    {name: "PositionKey", size: 256, indexed: true },
    {name: "Opener"     , size: 160, indexed: true },
    {name: "EtherTossed", size: 256, indexed: false},
    {name: "OddEven"    , size:   8, indexed: false},
];

function decode(data) {
    let event = {};
    let index = "0x".length;
    for (let i = 0; i < EVENT.length; i++) {
        if (!EVENT[i].indexed) {
            let name = EVENT[i].name;
            let size = Math.floor(EVENT[i].size / 4);
            event[name] = web3.toBigNumber("0x" + data.substr(index, size));
            index += size;
        }
    }
    return event;
}