Like Bytes32, ContractId is a wrapper on [u8; 32] with similar methods and implements the same traits (see fuel-types documentation ).
These are the main ways of creating a ContractId:
use std::str::FromStr;
use fuels::types::ContractId;
// Zeroed Bytes32
let contract_id = ContractId::zeroed();
// Grab the inner `[u8; 32]` from
// `Bytes32` by dereferencing (i.e. `*`) it.
assert_eq!([0u8; 32], *contract_id);
// From a `[u8; 32]`.
let my_slice = [1u8; 32];
let contract_id = ContractId::new(my_slice);
assert_eq!([1u8; 32], *contract_id);
// From a string.
let hex_str = "0x0000000000000000000000000000000000000000000000000000000000000000";
let contract_id =
ContractId::from_str(hex_str).expect("failed to create ContractId from string");
assert_eq!([0u8; 32], *contract_id);