---
title: "init(forAggregate:)"
framework: foundation
role: symbol
role_heading: Initializer
path: "foundation/nsexpression/init(foraggregate:)"
---

# init(forAggregate:)

Creates an aggregate expression for a specified collection.

## Declaration

```swift
init(forAggregate subexpressions: [NSExpression])
```

## Parameters

- `subexpressions`: A collection object (an instance of NSArray, NSSet, or NSDictionary) that contains further expressions.

## Return Value

Return Value A new expression that contains the expressions in collection.

## See Also

### Creating a Collection Expression

- [init(forUnionSet:with:)](foundation/nsexpression/init(forunionset:with:).md)
- [init(forIntersectSet:with:)](foundation/nsexpression/init(forintersectset:with:).md)
- [init(forMinusSet:with:)](foundation/nsexpression/init(forminusset:with:).md)