Fruit and chocolate both contain one of the many different types of sugar, some of which I have here on the table in front of me.
This one (jar furthest away) is sugar called glucose which comes from chocolate (cocoa) like the chocolate here (which tastes really good!) The next jar along, contains a sugar called fructose, which again is found in fruit and gives it that sweet taste. Then there's sucrose, which comes from sugar cane or sugar beet - the way sugar tastes is a combination of glucose and fructose. Next we have maltose and then lactose. You might know that lactose is found in milk - it's what gives milk its taste.
All of these sugars taste sweet, are soluble in water and they all contain carbohydrates - CHO which is a simple, short chain, molecule; all of these sugars contain CHO but in varying quantities which gives them different structures.