The Confusion of Smart Contracts

1

Dear guy
Can a smart contract write data only by using the app_global_put opcode in the contract? Like this
byte “6”
byte “00:00:00:00:00:04 1 1 1”
app_global_put
Can I write the data via sdk?
If the function to read in data is readGlobalState, what is the function to write data in sdk

2

Only stateful smart contracts can write state. The sdks do support calling stateful contracts and you can also add up to 1kb note to any transaction using the sdks.