c - 为什么 float 除以整数返回一个 float

Question

我正在学习 C。我想知道为什么你得到一个 float ，即使你的一个变量是一个整数。

float x = 5.0;
int y = 2;

float result = x / y;

我猜结果是 2.00000。但它确实返回一个 float (2.500000)

我认为它会是 2.000000，因为如果你除以 2 个整数就是结果。而且我认为，如果您使用 int 和 float，它会选择最不精确的值。

Answer 1

因为 C 的通常的算术转换。

引用 ANSI C 标准 § 3.2.1.5 常用算术转换:

Many binary operators that expect operands of arithmetic type cause conversions and yield result types in a similar way. The purpose is to yield a common type, which is also the type of the result. This pattern is called the usual arithmetic conversions: First, if either operand has type long double, the other operand is converted to long double . [...] Otherwise, if either operand has type float, the other operand is converted to float.

强调我的。