为什么一些后缀有必要吗？ [英] Why are number suffixes necessary?

问题描述

C＃语言（和其他语言我敢肯定），要求在数字文字的结尾后缀。这些后缀表明文字的类型。例如， 5M 是一个十进制数， 1006米是一个浮点数。

The C# language (and other languages I'm sure) require suffixes at the end of numeric literals. These suffixes indicate the type of the literal. For example, 5m is a decimal, 5f is a floating point number.

我的问题是：这些后缀确有必要，或者是有可能从它的上下文推断出一个文字的类型

My question is: are these suffixes really necessary, or is it possible to infer the type of a literal from its context?

例如，代码十进制D = 5.0 应推断 5.0 是不是双，但小数。 ？请问那种语法原因问题

For example, the code decimal d = 5.0 should infer that 5.0 is not a double, but a decimal. Does that kind of grammar cause problems?

推荐答案

这是对简单的场合，如：

That's fine for simple cases like:

float f = 7;

但它远不如做个明确的，这样你就不用担心类似的语句：

but it's far better to be explicit so that you don't have to worry about statements like:

float f = (double)(int)(1 / 3 + 6e22 / (double)7);

是的，我知道这是一个人为的例子，但我们的不的认识编码器从刚刚类型左边的意图的尤其的，如果它没有被分配给所有的变量（如作为参数传递给一个重载函数，可以带参数之一传递，浮动，双，小数等）。

Yes, I know that's a contrived example but we don't know the intent of the coder from just the type on the left, especially if it's not being assigned to a variable at all (such as being passed as an argument to an overloaded function that can take one of int, float, double, decimal et al).

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