How much apple is a half cup?

There is no equivalence.

A gram is a measure of mass. A cup is a measure of volume. The two measure different things and, according to basic principles of dimensional analysis, conversion from one to the other is not valid.

If you are not convinced, consider a cup of whipped cream or egg white. How many grams? Next consider a cup of treacle. How many grams?

The masses of equal volumes of the two substances will clearly be very different. So there is no direct conversion between mass and volume: you need to know the density of the substance to enable you to carry out the conversion.