What's the use of Java Random?
This article mainly introduces the use of Java Random, the article is very detailed, has a certain reference value, interested friends must read it!
The Random class is located under the java.util package, and instances of this class are used to generate random numbers.
Case 1:
Import java.util.Random
Import java.util.Scanner
Public class RandomDemo {
Public static void main (String [] args) {
/ / the system generates a random number between 1 and 100
Random r = new Random ()
/ / get random number
Int number = r.nextInt (100) + 1
/ / guess the data many times
While (true) {
/ / enter the data to be guessed by the keyboard
Scanner sc = new Scanner (System.in)
System.out.println ("Please enter the data you guessed (range 1100):")
Int guessnumber = sc.nextInt ()
/ / compare two data and use if statement to realize
If (guessnumber > number) {
System.out.println ("you guess the data is too big")
} else if (guessnumber < number) {
System.out.println ("your guess is small")
} else {
System.out.println ("Congratulations, you guessed right")
Break
}
}
}
}
Running result:
Please enter the data you guessed (range 1-100):
twelve
The number you guessed is small.
Case 2:
Import java.util.Random
Public class CallName {
Public static void main (String [] args) {
System.out.println ("students in the class:")
String [] arr = {"zhangsan", "lisi", "wangwu", "sjls", "qianqi"}
For (int I = 0; I < arr.length;i++) {
System.out.print ("student number" + (item1) + ":" + arr [I] + "")
}
System.out.println ()
/ / use random numbers for roll call
Random ran = new Random ()
Int index = ran.nextInt (arr.length)
System.out.println ("student number" + (index+1) + ":" + arr [index] + "")
}
}
Running result:
The students in the class are:
Student number 1: zhangsan student number 2: lisi student number 3: wangwu student number 4: sjls student number 5: qianqi
Student number 3: wangwu
Case 3:
Import java.util.*
Public class V {
Public static void main (String [] args) {
Int a [] = new int [100]
For (int iTuno Bandi)
