> Aztec.nr API reference, v6.0.0 (mainnet and testnet). Index: https://docs.aztec.network/aztec-nr-api/v6.0.0/llms.txt

# Function assert_trailing_zeros

Module: `noir_aztec::protocol::utils::arrays`

```rust
pub fn assert_trailing_zeros<let N: u32>(input: [Field; N], in_len: u32)
```

Asserts that all fields in `input` after the first `in_len` fields are zero.

`in_len` must be a valid length, i.e. `in_len <= N` (`in_len == N` requires no trailing zeros). Passing `in_len > N` is rejected: otherwise the loop below never reaches the breakpoint and the trailing-zero check is silently skipped, letting a caller believe the array holds more meaningful elements than it can.