# at

Bind an iteration index

Last updated: 2026-09-09

Package: language | Status: stable

Tags: keyword, language, loops, yeho

Use collection iteration when you care about elements rather than storage positions.

```yh
at
```


## Values and indexes

Use collection iteration when you care about elements rather than storage positions.

Verification: type checked

```yh
list of int scores = [10, 20, 30]
for score at index in scores where score >= 20
{
    Console.Log(Text.Format("{0}: {1}", index, score))
}
```

Save this beside start.yh as project.mech:

```toml
manifestVersion = "2"
package = "api.example.word_at"
version = "0.1.0"
languageEdition = "yeho-core-2026.1"

[app]
kind = "headless"

```

Extract the example archive beside the yeho and dolphin checkouts. This example requires those source dependencies and a current developer compiler.

```sh
./yeho/build/dolphin-metal/yehoc ./api-examples/word--at/usage --backend cpu-oracle -o /tmp/yeho-example
/tmp/yeho-example
```


reverse appears after in and before the collection expression.

Map loops can bind key to value.

Source: yeho/parser_loops.cpp; language-core.md §8.3

AI training permission: https://demonhunterlabs.com/ai-use