The order of elements from an input array

Question

I have this function, which is receiving a wallet address and an array of tokens, and returns the balances of every token for this wallet.

function getBalances(address wallet, IERC20[] tokens) external view returns (uint256[] memory balances) {

    uint size = tokens.length;

    uint256[] memory balances = new uint256[](size) 
    for (uint i=0; i < size; i++) {
            
        TokenContract tokenContract = TokenContract(tokens[i]);

        balances[i] = tokenContract.balanceOf(wallet);

    }
        
    return balances;

}

But I am concerned about the order of the input tokens. If the order is the same like the user sent them.

For example: user sends [t1, t2, t3, t4], for-loop is iterating in the same order, and the return is like [b1, b2, b3, b4].

Or the order is not 100% guaranteed? In this case, can you give me an idea about how to return the balances for the user to be able to know which token represents?

Answer 1

The order of tokens here is indeed the same as the one provided by the caller of getBalances, so as you said:

user sends [t1, t2, t3, t4], for-loop is iterating in the same order, and the return is [b1, b2, b3, b4].

where bi is the ti's balance for wallet.