wolfram-mathematica - Matematica If 语句

Question

在 Mathematica 中，我使用以下代码：

If[ x [[1]] <= 4 && x [[2]] <= 4, "True","False"]
True

这是我感到困惑的地方：

If[ True, count=count + 1, count=count]

我不知道如何从代码之前的行中获取答案

Answer 1

为什么不只是

If[ x [[1]] <= 4 && x [[2]] <= 4, count++]

?

Answer 2

除了贝利撒留的回答之外，您还可以考虑：

count += Boole[x[[1]] <= 4 && x[[2]] <= 4]

另外，您说：“我不知道如何从代码之前的行中获取答案。”

你可以使用%：

If[ x [[1]] <= 4 && x [[2]] <= 4, True, False];

If[%, count=count + 1, count=count]

Answer 3

Literally you could just fit one piece of code inside the other:

If[ 
   If[ x [[1]] <= 4 && x [[2]] <= 4, True, False],
   count=count + 1, count=count
]

Note that the strings "True" and "False" have been replaced with their logical values True and False