Returned Data

Returned data are variables that are created automatically when executing FCT. This variables holds all the returned values from previous called functions of the current FCT execution.

How to use

The returned data are kept in bytes format for each call. That means that in order to use a variable there is a need to tell the FCT engine from what call and with what offset the value exist.

Usage

0xFD000....TTTTTTLLLL LLLL holds the call number (starting with 1) TTTTTT holds the offset in bytes inside the call

0xFD00000000000000000000000000000000600003 means the 64-96 bytes of the returned data from the third call on the FCT will be used

FD stands for "Future Data"

0xFDB000....TTTTTTLLLL LLLL holds the call number (starting with 1) TTTTTT holds the reverse offset (backwards) in bytes inside the call

0xFDB0000000000000000000000000000000000003 means the last 32 byes of the returned data from the third call on the FCT will be used

FDB stands for "Future Data in Backwards"

External variable use four range of values: For address types: 0xFD00000000000000000000000000000000000001 ... 0xFD0000000000000000000000000000ffffffffff and 0xFDB0000000000000000000000000000000000001 ... 0xFDB000000000000000000000000000ffffffffff For uint256 and bytes32 types:

0xFD00000000000000000000000000000000000000000000000000000000000001 ... 0xFD0000000000000000000000000000000000000000000000000000ffffffffff and 0xFDB0000000000000000000000000000000000000000000000000000000000001 ... 0xFDB000000000000000000000000000000000000000000000000000ffffffffff

Call number must be smaller than the current running call