如何将两个16位整数（高位字/低位字）转换为32位浮点数？

Question

I have two 16bit integer raw data.

For example:
High Word = 17142 (dec) or 0100001011110110 (binary)
Low Word = 59759 (dec) or 1110100101111001 (binary)

If you treat two word together as one 32bit float data, it will be "123.456"
Binary --> 01000010111101101110100101111001

How to convert integer array [59759 , 17142] to float 123.456 in Javascript?

Note: [ X (16bit low word) , Y (16 bit high word) ] ==> Z (32bit float)

Answer 1

You can do this with typed arrays and ArrayBuffer , which allow you to interpret the same bits in different ways (but endianness is platform-specific). It's also possible using a DataView on the buffer, which lets you conrol endianness.

Here's the typed array approach which works with the endianness of my platform, see comments:

 // Create a buffer var buf = new ArrayBuffer(4); // Create a 16-bit int view of it var ints = new Uint16Array(buf); // Fill in the values ints[0] = 59759; ints[1] = 17142; // Create a 32-bit float view of it var floats = new Float32Array(buf); // Read the bits as a float; note that by doing this, we're implicitly // converting it from a 32-bit float into JavaScript's native 64-bit double var num = floats[0]; // Done console.log(num); 

Here's the DataView approach, note writing the ints in the opposite order:

 // Create a buffer var buf = new ArrayBuffer(4); // Create a data view of it var view = new DataView(buf); // Write the ints to it view.setUint16(0, 17142); view.setUint16(2, 59759); // Read the bits as a float; note that by doing this, we're implicitly // converting it from a 32-bit float into JavaScript's native 64-bit double var num = view.getFloat32(0); // Done console.log(num);