What are the transaction return object attributes "c," "e," and "s" in an integer / uint return type? [duplicate]

Question

I have a counter in a Solidity contract:

uint8 public transactionCounter;
function ContractConstructor() public {
    transactionCounter = 0;
}

function getTransactionCounter() returns (uint8) {
    return transactionCounter;
}

function trns() {
    transactionCounter += 1;
}

When interacting with the contract, i get back the transactionCounter

App.contract.XYContract.deployed()then(function(instance){
    return instance.getTransactionCounter.call();
}).then(function(counter) {
    console.log(counter);
});

In the JavaScript console, I get:

e {s: 1, e: 0, c: Array(1)}

What are s, e and c and where is it documented?

Answer 1

If the return value of a call is a number, you'll get back a BigNumber. You can use counter.toString() or counter.toNumber() (though note that the latter may lose precision on large numbers, which is why BigNumber exists in the first place).

Read more in the web3.js documentation.