# `GSLayer metricForName:`

*Instance Method*

Master metric value for a metric name.

## Declaration

```objc
- (CGFloat) metricForName:(NSString *) key;
```

```python
metricForName_(key: str) -> float
```

## Parameters

- `key` — The metric name to resolve.

## Discussion

Returns `NSNotFound` when no matching metric exists.

## See Also

### Master Metrics

- [`GSMetricStore`](/Core/GlyphsCore/GSMetricStore)
- [`GSLayer metrics`](/Core/GlyphsCore/GSLayer/metrics) — Vertical metrics for the associated master.
- [`GSLayer metricsForMaster:`](/Core/GlyphsCore/GSLayer/metricsForMaster:) — Vertical metrics for a master.
- [`GSLayer metricForType:`](/Core/GlyphsCore/GSLayer/metricForType:) — Master metric value for a metrics type.
- [`GSLayer isSecondaryMetric:`](/Core/GlyphsCore/GSLayer/isSecondaryMetric:) — Whether a metric is secondary for the layer’s glyph case.
- [`GSValueStore`](/Core/GlyphsCore/GSValueStore)
- [`GSLayer stemsForMaster:`](/Core/GlyphsCore/GSLayer/stemsForMaster:) — Stem values for a master.