How to get back a float when added as bytes to a NSMutableData

Asked Dec 15 '15 at 14:33

Active Dec 15 '15 at 15:31

Viewed 69 times

I am appending floats to a NSMutable to get a bytestream of a lot of floats.

for var i=0 ;i < 10000 ;i++{

   let myfloat=floatarray[i];
   testdata.appendBytes(&myfloat, length: sizeof(Float));
}

How do I get the array back from that stream ?

UPDATE

Thanks to Mike. I did as suggested.

// Have to cast the pointer to the right size
        let pointer = UnsafePointer<Float>(testdata.bytes)
        let count = testdata.length / sizeof(Float);

        // Get our buffer pointer and make an array out of it
        let buffer = UnsafeBufferPointer<Float>(start:pointer, count:count)
        let array = [Float](buffer)


        print(String(array[0]));

edited Dec 15 '15 at 15:31

asked Dec 15 '15 at 14:33

mcfly soft

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You can use `subdataWithRange:`. – Larme Dec 15 '15 at 14:36
What are you attempting to accomplish be appending to an `NSMutableData`? – zaph Dec 15 '15 at 14:54
what the type is NSMutable ? – user3441734 Dec 15 '15 at 14:55
@user3441734 See the question title. – zaph Dec 15 '15 at 15:04
This http://stackoverflow.com/a/24516400/1187415 works with a Float (or any other "scalar") array as well ... – Martin R Dec 15 '15 at 15:06
Now if the Question code only compiled. It would also be nice it it used Swift syntax and variable CamelCase. – zaph Dec 15 '15 at 15:20
@zaph. I do this, because I realized, that this is the fastest way to write/read a lot of floats into/from a blobfield in SQLite. – mcfly soft Dec 15 '15 at 15:22
@Maritn . Thank you very much. Got it to work. I updated the question with the solution. – mcfly soft Dec 15 '15 at 15:31

How to get back a float when added as bytes to a NSMutableData

0 Answers0