Java Random nextInt（）方法与示例

随机类nextInt()方法 (Random Class nextInt() method)

Syntax:

句法：

    public int nextInt();
public int nextInt(int num);

nextInt() method is available in java.util package.
nextInt()方法在java.util包中可用。
nextInt() method is used to return the next pseudo-random value from this Random Value Generator.
nextInt()方法用于从此随机值生成器返回下一个伪随机值。
nextInt(int num) method is used to return the next pseudo-random distribute integer value between 0 and the given parameter (num) from this Random Generator.
nextInt(int num)方法用于从此随机数生成器返回下一个介于0和给定参数(num)之间的下一个伪随机分布整数值。
These methods may throw an exception at the time of returning the next integer value.
这些方法在返回下一个整数值时可能会引发异常。

IllegalArgumentException: This exception may throw when the given parameter (num<0) is invalid.
IllegalArgumentException ：当给定参数(num <0)无效时，可能引发此异常。
These are non-static methods and it is accessible with the class object and if we try to access these methods with the class name then also we will get any error.
这些是非静态方法，可通过类对象进行访问，如果尝试使用类名访问这些方法，则也会遇到任何错误。

Parameter(s):

参数：

In the first case, nextInt()
在第一种情况下， nextInt()
- It does not accept any parameter.
In the second case, nextInt(int num)
在第二种情况下， nextInt(int num)
- int num – represents the last endpoint of this Random Value Generator.
- int num –表示此随机值生成器的最后一个端点。

Return value:

返回值：

In both the cases, the return type of the method is int – it returns next pseudorandom distributed value between 0 and num.

在这两种情况下，方法的返回类型均为int –它返回0至num之间的下一个伪随机分布值。

Example:

例：

// Java program to demonstrate the example 
// of nextInt() method of Random
import java.util.*;
public class NextIntOfRandom {
public static void main(String args[]) {
// Instantiates Random object
Random ran = new Random();
// By using nextInt() method is
// to return next int pseudo-random
// value by using Random Value Generator
int val = ran.nextInt();
// Display val
System.out.println("ran.nextInt(): " + val);
// By using nextInt(int) method is
// to return next int pseudo-random
// value between 0 and the given value
// and 0 is inclusive whereas the given value 
// is exclusive by using Random Value Generator
val = ran.nextInt(50);
// Display val
System.out.println("ran.nextInt(50): " + val);
}
}

Output

输出量

RUN 1:
ran.nextInt(): -1450643138
ran.nextInt(50): 13
RUN 2:
ran.nextInt(): 1448295644
ran.nextInt(50): 47
RUN 3:
ran.nextInt(): 397396236
ran.nextInt(50): 11