It is quite clear - && is a binary operator and you need to use a boolean operand for it.
Here:
if((number[i]>100) && (number[i]<200) && (number[i]/7))
(number[i]/7)
is a number, and it does not qualify to be an operand of && operator.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…