如何让我的代码选择从X到Y的数字？

问题描述

import java.util.Random;

import java.lang.Math;



public class Exercise_7_8e {



public static void main（String [] args）{

// TODO自动生成方法存根



float [] Array1 = new float [99];



float max = Array1 [0];

float min = Array1 [0];



for（int i = 0; i< Array1.length; i ++）{

Array1 [i] =（int）（Math.random（）* 200 + 6）;

if（Array1 [i]> max）{

max = Array1 [i];

}否则if（Array1 [i]< min）

min = Array1 [i];



}



System.out.println（最大值是+最大值）;

System.out.println（最小值是+ min;



}



}



输出：



最大值是205.0

最小值是0.0



我尝试过：



所以Math.random（）的格式化应该是Math.random（）* max + min正确吗？但是，在我的代码中，输出将始终返回0作为min。我如何解决这个问题？

import java.util.Random;
import java.lang.Math;

public class Exercise_7_8e {

public static void main(String[] args) {
// TODO Auto-generated method stub

float[] Array1 = new float[99];

float max = Array1[0];
float min = Array1[0];

for (int i = 0; i < Array1.length; i++) {
Array1[i] = (int) (Math.random() * 200 + 6);
if (Array1[i] > max) {
max = Array1[i];
} else if (Array1[i] < min)
min = Array1[i];

}

System.out.println("The largest value is " + max);
System.out.println("the smallest value is " + min);

}

}

Output:

The largest valus is 205.0
the smallest value is 0.0

What I have tried:

So the formatting of Math.random() is supposedly Math.random()*max + min correct? However, in my code the output will always return 0 as the min. How do i fix this?

推荐答案

float[] Array1 = new float[99];<br />
float min = Array1[0];

从未初始化的数组中分配 min 。到目前为止，我知道Java它默认初始化为'0'。我的个人观点：总是明确地初始化变量而不依赖于编译器/链接器行为。



所以 Math.random（）* 200 + 6 永远不会< min意味着< 0（来自默认初始化）。



尝试 - 并考虑它的含义：

float min = 9999999.9 或者更好的max（浮动）如果它确实存在于Java中（我认为它是Float.MAX_VALUE）



我希望它帮助。

You assign min from a not initialiezed Array. So far I know Java it does initialize by Default to '0'. My personal opinion: Always initialize variables explicitely and don't rely on Compiler/Linker behaviours.

So Math.random() * 200 + 6 will never be < min which means < 0 (from the Default init).

Try - and think about what it means:
float min = 9999999.9 or much better to max(float) if it does exists in Java (I think it is Float.MAX_VALUE)

I hope it helps.

引用：

因此Math.random（）的格式化应该是Math.random（ ）* max + min是否正确？

So the formatting of Math.random() is supposedly Math.random()*max + min correct?

简单阅读文档分析会告诉你答案。

A simple reading of documentation an analyze would tell you the answer.

0 <= Math.random() < 1
0 <= Math.random() * 200 < 200
6 <= Math.random() * 200 + 6 < 206
6 <= (int) (Math.random() * 200 + 6) < 206
6 <= (int) (Math.random() * 200 + 6) <= 205

Quote：

但是，在我的代码中，输出将始终返回0作为min。我如何解决这个问题？

However, in my code the output will always return 0 as the min. How do i fix this?

问题是你初始化 min 0，这已经低于你的任何随机值得到。



请注意，您不需要将每个随机值存储在数组中，因为您不会重复使用它们。

The problem is that you initialize min with 0 which is already lower than any random value that you get.

Note that you don't need to store each random values in an array because you don't reuse them.

这篇关于如何让我的代码选择从X到Y的数字？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！