c is a random value, and in c , how a random number is generated

Uh, you asked it just now, right?!Again?!

arraylist arr = new arraylist();

random rd = new random();

for (int i = 0; i < 100; i++)101));

foreach (int i in arr)if ((i % 2) == 0)

i + ",";Output an even number.

i + ",";Output odd numbers.

We can initialize a random number generator in two ways;

The first method does not specify a random seed, and the system automatically selects the previous random seed in the current tense

random ra=new random();

The second way is to specify an int argument as a random seed:

int iseed=6;random ra=new random(iseed);

Now we're going to use the method to generate random numbers.

He returns a random integer multiple of an ised integer number.

1. The next method of the random class, which generates a random number between two integers. The syntax format is:

public virtual int next（int min value，int max value）；

2. Generate random numbers for the specified interval:

random random = new random();

int n = ,20);Generate random numbers between 10-20.

int n1 = ,80);Generate random numbers between 60-80.

To achieve this, you have to understand firstrandom()

Method. In c there is a parameterless method and a parametric method:

public random();The program takes the milliseconds of the current date as the seed, so the seed will be different each time.

public random(int seed);A seed of a random number, and a seed corresponds to a fixed random number in a range.

What is the relationship between that kind of sub and random number?

The random function produces a pseudo-random number, which is actually a sequence generator, with a fixed algorithm, only when the seeds are different, the sequences are different, if the seed is fixed in the program, the generated random number will always be fixed.

random ro = new random(5);

int a;

a = , 20);

Functions are used like this, such as random numbers from 100 to 999.

random ran=new random();

int randkey=,999);

However, there will be repetitions, and random can be given a system time as a parameter to generate random numbers, and there will be no repetitions.

The first method does not specify a random seed, and the system automatically selects the previous random seed in the current tense

random ra=new random();

The second way is to specify an int argument as a random seed:

int iseed=6;

random ra=new random(iseed);

Now we're going to use the method to generate random numbers.

It returns a number greater than or equal to zero but less than 2,147,483,647, which is not enough for our needs, and we will describe its overloaded function and some other methods below.

public virtual int next(int);

Usage: Returns a positive random number that is less than the specified maximum value (20 here).

public virtual int next(int minvalue, int maxvalue);

Usage:,20).

Returns a random number within a specified range (in this case, between 1-20), which we'll use in the following example.

There are also several methods of the class, which are:

Public method: nextbytes populates the elements of the specified byte array with random numbers.

nextdouble returns a random number between and .

Protected Methods:

sample returns a random number between and and only allows access to subclass objects.

random ran = new random();

100);1 is the minimum value and 100 is the maximum value.

In the development process, it is often necessary to generate random numbers, such as static generation.

In the case of HTML web pages, the file name is usually obtained by generating a random number, and when generating an order, the order number can also be obtained by generating a random number, etc. At. c#

, generally used.

random

Generates random numbers, which can arbitrarily specify the range of random numbers generated. random

Combined with arrays, some special range of random numbers can be generated to meet special needs.

1. Use. random

Generates a random number for the specified range.

1. Generate random numbers with a specified upper limit (such as random numbers within 100).

random

rannew

random();intn

2. Generate random numbers with specified upper and lower limits (such as random numbers from 100 to 1000).

random

rannew

random();intn

Second, use. random

Combine arrays to produce random numbers in a specified range.

In some cases, random numbers can only take some specially specified values, such as non-consecutive numbers or specified words, etc., and only use them in this case.

random

If you can't meet the requirements, you have to borrow an array to do so. The idea is to store these special values in an array, and then take the length of the array.

random

The upper limit of the array produces a random number, which is the subscript of the array, and the value of the array is obtained from this subscript.

1. Example 1.

If you want to generate discontinuous random numbers, ** is as follows:

public

string

getrandom(string

arr)random

rannew

random();intn

return

arr[n];

Call method: stringarr

getrandom(arr);

2. Example 2.

If you want to use a specified word as the value of a random number, the implementation is the same as example 1, the difference is only the value of the random number, so you only need to define an array of words to call the above directly.

Call method: string

arrred",green",blue",orange",white"

getrandom(arr);

The above two methods for generating specified random numbers have passed the test and can be flexibly selected according to the actual development needs, and are generally used directly.

random

That's it.