# `GSShape compareString`

*Instance Method*

A structural description used to determine layer compatibility.

## Declaration

```swift
func compareString() -> String?
```

```objc
- (NSString *) compareString;
```

```python
compareString() -> str
```

## Discussion

The description does not represent complete shape equality. `nil` indicates that the shape does not participate in compatibility comparisons.

## See Also

### Type and Comparison

- [`GSShapeType`](/Core/GlyphsCore/GSShapeType) — The kind of content represented by a shape.
- [`GSShape.shapeType`](/Core/GlyphsCore/GSShape/shapeType) — The kind of content represented by the concrete shape.
- [`GSShape isEqualToShape:`](/Core/GlyphsCore/GSShape/isEqualToShape:) — Whether another shape has the same concrete class.