Transfering data to Metal MTLBuffer dynamically in Objective-c

I have a following MTLBuffer created. How can I send INPUTVALUE to the memINPUT buffer? I need to send repeatedly in Objective-C.

// header file
@property id<MTLBuffer> memINPUT;

// main file
int length = 1000;
...
memINPUT = [_device newBufferWithLength:(sizeof(float)*length) options:0];
...
float INPUTVALUE[length];
for (int i=0; i < length; i++) {
	INPUTVALUE[i] = (float)i;
}

// How to send to INPUTVALUE to memINPUT?
...

The following is Swift version. I am looking for Objective-c version.

memINPUT.contents().copyMemory(from: INPUTVALUE, byteCount: length * MemoryLayout<Float>.stride);