Why can't I use || or && with double as in sample below?

```
if (((mDiameter = 1 || mDiameter = 1.2) && mPitch = 0.25) || (mDiameter = 1.6 && mPitch = 0.35) || (mDiameter = 2 && mPitch = 0.4)
|| (mDiameter = 2.5 && mPitch = 0.45) || (mDiameter = 3 && mPitch = 0.5) || (mDiameter = 4 && mPitch = 0.7)
|| (mDiameter = 5 && mPitch = 0.8) || (mDiameter = 6 && mPitch = 1) || (mDiameter = 8 && mPitch = 1.25)
|| (mDiameter = 10 && mPitch = 1.5) || (mDiameter = 12 && mPitch = 1.75) || (mDiameter = 16 && mPitch = 2)
|| (mDiameter = 20 && mPitch = 2.5) || (mDiameter = 24 && mPitch = 3) || (mDiameter = 30 && mPitch = 3.5)
|| (mDiameter = 36 && mPitch = 4) || (mDiameter = 42 && mPitch = 4.5) || (mDiameter = 48 && mPitch = 5)
|| (mDiameter = 56 && mPitch = 5.5) || (mDiameter = 64 && mPitch = 6)) {
mDesignation = "METRIC COARSE - 2nd CHOICE";
} else if (mDiameter = 11 && mPitch = 1.5)
{
mDesignation = "METRIC COARSE - 3rd CHOICE";
```

.......................................... etc