如果您关心@Daap对已接受答案的注释，并且只能传递一次值，则可以尝试以下方法之一

bool TestRangeDistance (int numberToCheck, int bottom, int distance)
{
  return (numberToCheck >= bottom && numberToCheck <= bottom+distance);
}

//var t = TestRangeDistance(10, somelist.Count()-5, 10);

or

bool TestRangeMargin (int numberToCheck, int target, int margin)
{
  return (numberToCheck >= target-margin && numberToCheck <= target+margin);
}

//var t = TestRangeMargin(10, somelist.Count(), 5);

In production code I would simply write 1 <= x && x <= 100 This is easy to understand and very readable. Starting with C#9.0 we can write x is >= 1 and <= 100 Note that we must write x only once. is introduces a pattern matching expression where and is part of the pattern. && would require us to repeat x is as in x is >= 1 && x is <= 100 Here is a clever method that reduces the number of comparisons from two to one by using some math. There is not necessarily a performance advantage in doing so, but it is elegant. The idea is that one of the two factors becomes negative if the number lies outside of the range and zero if the number is equal to one of the bounds: If the bounds are inclusive: (x - 1) * (100 - x) >= 0 or (x - min) * (max - x) >= 0 If the bounds are exclusive: (x - 1) * (100 - x) > 0 or (x - min) * (max - x) > 0

如果您关心@Daap对已接受答案的注释，并且只能传递一次值，则可以尝试以下方法之一

bool TestRangeDistance (int numberToCheck, int bottom, int distance)
{
  return (numberToCheck >= bottom && numberToCheck <= bottom+distance);
}

//var t = TestRangeDistance(10, somelist.Count()-5, 10);

or

bool TestRangeMargin (int numberToCheck, int target, int margin)
{
  return (numberToCheck >= target-margin && numberToCheck <= target+margin);
}

//var t = TestRangeMargin(10, somelist.Count(), 5);

2022年6月

int id = 10;
if(Enumerable.Range(1, 100).Select(x => x == id).Any()) // true

In C, if time efficiency is crucial and integer overflows will wrap, one could do if ((unsigned)(value-min) <= (max-min)) .... If 'max' and 'min' are independent variables, the extra subtraction for (max-min) will waste time, but if that expression can be precomputed at compile time, or if it can be computed once at run-time to test many numbers against the same range, the above expression may be computed efficiently even in the case where the value is within range (if a large fraction of values will be below the valid range, it may be faster to use if ((value >= min) && (value <= max)) ... because it will exit early if value is less than min).

不过，在使用这样的实现之前，请先对目标机器进行基准测试。在某些处理器上，由两部分组成的表达式可能在所有情况下都更快，因为两个比较可能是独立完成的，而在减法和比较方法中，减法必须在比较执行之前完成。

你的意思是?

if(number >= 1 && number <= 100)

or

bool TestRange (int numberToCheck, int bottom, int top)
{
  return (numberToCheck >= bottom && numberToCheck <= top);
}