java中如何划分两个long型变量
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How to divide two long variables in java
提问by Arulmurugan
Sorry for the basic question, I have to divide the long variable by another long variable, but it returns 0. Can any one help
对不起，基本问题，我必须将 long 变量除以另一个 long 变量，但它返回 0。任何人都可以帮忙
long a = 3004230;
long b = 6793368;
long c = (a/b)*100;
回答by Rudi Kershaw
Literal Values and Literal Arithmatic
文字值和文字算术
There are a couple of issues with that code. Firstly, non-floating point literal valuesare of type intby default and so 3004230in your code is an int. To explicitly declare it a longuse 3004230Linstead.
该代码有几个问题。首先，默认情况下非浮点文字值是类型int的，因此3004230在您的代码中是int. 显式声明它是一种long用途3004230L。
Also, all arithmetic done with non-floating point literalsreturns an intresult unless casted specifically to a floating point type such as floator double. As such (a/b)*100is less than 1, and therefore is truncateddown to 0 (the floating point values are just cut off). Also, even if it did return the same result you are trying to store it in a longwhich can not store floating point values.
此外，所有使用非浮点文字进行的算术运算都会返回int结果，除非专门转换为浮点类型，例如floator double。因此(a/b)*100小于 1，因此被截断为 0（浮点值被截断）。此外，即使它确实返回了相同的结果，您也试图将其存储在long无法存储浮点值的 a 中。
So, you should do something like the following to get the real result.
因此，您应该执行以下操作以获得真实结果。
long a = 3004230L; // Use the L notation to declare this literal a long.
long b = 6793368L;
double c = ((double)a/b)*100; /* casting your division result to (double) means
the result will not be 0 */
I hope this helps.
我希望这有帮助。
回答by Cengiz
final long a = 3004230;
final long b = 6793368;
final double c = ((double) a / b) * 100;
=> c = 44.22298335670907
=> c = 44.22298335670907
回答by Dawnkeeper
What you are doing right now is integer division. This will always return an integer/long result. You have to use a float or double to get a floating point result even if you cast it back to integer values afterwards.
你现在正在做的是整数除法。这将始终返回整数/长结果。您必须使用 float 或 double 来获得浮点结果，即使之后将其转换回整数值也是如此。
long c = (long)(a/(float)b*100);
回答by whhotw
try it.
尝试一下。
long a = 3004230;
long b = 6793368;
long c = ((long)((float)a/(float)b)*100); //answer=44
float c = ((long)((float)a/(float)b)*100); //answer=44.1256378
回答by sona
The long c you are creating isn't the value you expected. It is in the integer range. To create longs, use
您创建的 long c 不是您期望的值。它在整数范围内。要创建多头，请使用
final long c= 3004230L * 6793368L; By adding an L after the number literal, you tell the compiler to compile it as a long instead of an int.
最终长 c= 3004230L * 6793368L；通过在数字文字后添加 L，您可以告诉编译器将其编译为 long 而不是 int。
回答by rock321987
obviously the answer will be 0for above..as you can see when you divide
显然，答案将在0上面......正如你在划分时所看到的
3004230 / 6793368 = 0.442 = 0(when casted to
longtype)
3004230 / 6793368 = 0.442 = 0（当转换为
long类型时）
and
和
0 * any number = 0..
0 * 任何数字 = 0..
to convert it use this
转换它使用这个
double c = (a * 1.0/b)*100.0;
you have to use datatype that can store decimalvalue which is floator double..longcannot store decimal numbers
你必须使用可以存储decimal值的数据类型，float或者double..long不能存储十进制数
回答by vz0
You can do the same without casting to a float:
您可以在不强制转换为 a 的情况下执行相同操作float：
long a = 3004230L;
long b = 6793368L;
long c = (a * 100L)/b;
