# init(shape:dataType:) Creates a multidimensional array with a shape and type. ``` init(shape: [NSNumber], dataType: MLMultiArrayDataType) throws ``` ## Parameters `shape` An integer array that has an element for each dimension in a multiarray that represents its length. `dataType` An element type defined by [`MLMultiArrayDataType`](/documentation/CoreML/MLMultiArrayDataType). ## Discussion This method allocates a contiguous region of memory for the multiarray’s shape. You must set the contents of memory. The multiarray frees the memory in its deinitializer (Swift) or method (Objective-C). The following code creates a 3 x 3 multiarray and sets its contents to the value 3.14159. ```objc NSError *error = nil; // Create a 2D multiarray with dimension 3 x 3. NSArray *shape3x3 = @[@3, @3]; MLMultiArray *multiarray3x3 = [[MLMultiArray alloc] initWithShape:shape3x3 dataType:MLMultiArrayDataTypeFloat error: &error]; if (error != nil) { // Handle the error. return; } NSLog(@"Before: %@\n", multiarray3x3); // Initialize the multiarray. for (int x = 0; x < 3; x++) { for (int y = 0; y < 3; y++) { NSNumber *xSubscript = [NSNumber numberWithInt:x]; NSNumber *ySubscript = [NSNumber numberWithInt:y]; [multiarray3x3 setObject:@3.14159 forKeyedSubscript:@[xSubscript, ySubscript]]; } } NSLog(@"After: %@\n", multiarray3x3); ``` --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)