对单元格的数值进行自动判断
设单元格的值为：X
0<X<60，显示为字母D
60<X<70，显示为字母C
70<=X<=85,显示为字母B
85<X<100,显示为字母A
方法一：用IF函数嵌套
=IF(A1<60,"D",IF(A1<70,"C",IF(A1<=85,"B","A")))
方法二：函数CHOOSE、MATCH结合使用
=CHOOSE(MATCH(D1,{0,60,70,85},1),"D","C","B","A")
原文：https://www.cnblogs.com/tongxiaohu/p/12072470.html