How do I compute the JSON-RPC quantity value?

[siddharthaDevineni]

Hi,

I just found that it gives an incorrect value, I am using ethers 6.11.1
Thank you.

[ricmoo]

The ASCII bytes for the string "5" is [ 0x35 ]. Number are super easy to convert by hand, for example 0 is 0x30 and "9" is 0x39 so the ASCII string "123" in hex is "0x313233". Any value under 32 is a non-printable character. All ASCII7 values are their own-UTF8 equivalents.

Here is the chart: https://en.m.wikipedia.org/wiki/ASCII

I’m no t quite sure what type of conversion you are trying to do, in terms of padding, but if you can give an example of what you are trying to do, I can tell you which function(s) you want to use. But I don’t think UTF8 is your desired encoding based on your question. :)

[siddharthaDevineni]

Hi Richard,
Thank you for your reply. Okay, maybe I am using the wrong function for my purpose. Actually, I wanted to have a hex representation of a "value" in "string" of the amount of ETH to send using "eth_sendTransaction" method through Metamask Ethereum API, for example:

const valueInHex = ethers.hexlify((ethers.toUtf8Bytes(ethers.parseEther(value))))

Here i am converting ETH to Wei and then converting that Wei value to bytes and having a hex value of it. But as you said i was getting ASCII bytes for the value i provided.

This is how i did a workaround for now:

const valueinHex = "0x" + parseInt(ethers.parseEther(value)).toString(16);

Do you have any suggestions? Thank you.

[ricmoo]

Never use parseInt for anything related to Ethereum or blockchain, as it will use IEEE 754 JavaScript numbers which implicitly round. If you find yourself using it, definitely think through what you are trying to do and whether any form of rounding will bite you. :)

The JSON-RPC calls expect a “quantity”, so I expect you just need ethers.toQuantity("5") (see toQuantity).

Let me know if that works. :)

[siddharthaDevineni]

Thank you very much for the suggestion, it has worked :)