How to convert data into little endian format?

Question

var val = 1240;

convert into little endian formate swift 3

Ex: 1500 (0x5DC) to 0xDC050000

Answer 1

let value = UInt16(bigEndian: 1500)

print(String(format:"%04X", value.bigEndian)) //05DC
print(String(format:"%04X", value.littleEndian)) //DC05

Make sure you are actually using the bigEndian initializer.

With 32-bit integers:

let value = UInt32(bigEndian: 1500)

print(String(format:"%08X", value.bigEndian)) //000005DC
print(String(format:"%08X", value.littleEndian)) //DC050000

Answer 2

If you want 1500 as an array of bytes in little-endian order:

var value = UInt32(littleEndian: 1500)

let array = withUnsafeBytes(of: &value) { Array($0) }

If you want that as a Data:

let data = Data(array)

Or, if you really wanted that as a hex string:

let string = array.map { String(format: "%02x", $0) }.joined()