To "speed up a transaction" there's only one possible option: to send a new transaction with higher gas price but with the same nonce. This way if nodes see both of the transactions they will most likely pick up the one with the higher gas price and once that is mined the other transaction becomes invalid (a tx with that nonce has already been mined) and is ...
If I make this function without payable and don't take any money from the caller then return value accurately returns me the code.
You are on the right track but misinterpreting what you see. I'll break it down.
accurately returns me the code
I think you mean returns(string memory).
Payable has nothing to do with it. You have to ...
To see your token balance in metamask, you has to add your ERC20 token address in metamask.
->Click menu in top left corner of metamask popup
->Click 'Add Token'
->Select custom token and paste your token address in given field
->Then click next and after that click 'Add tokens'
Now token balance for your address will be displayed on metamask and you can ...
Infura is a public hosted node. It has no way to unlock your local accounts. Even if there was a way, it would be a security risk because anyone can connect to the same node and transfer your funds.
In order to send a transaction over Infura you will need to sign the transaction locally using web3.eth.sendRawTransaction(). The following example is from the ...