Random and Scanner in Java and their looping statements

1.1. function and usage of scanner class and Random class

Scanner is the default to read numbers by line. Create a function to enter
First Step: Guide package: Import Java.util.Scanner; Step two: Scanner scan=new Scanner (System. inch );//system.in is a third step from the console: Then receive this value with a variable class
        int n=scan.nextint ();

          common methods :public int nextint () : Get keyboard input data, return to int type

                     public String Next () : Get keyboard input data, return string

  
  2.Random method is a pseudo-randomly generated number method  
 Span style= "font-size:15px" > First step: Guide package: Import Java.util.Scanner;   Step two: definition:  Random scan   = new  Random ();   
   step three: int N=scan.nextint ();      //If there are values in parentheses, such as: 10, randomly generate 0 to 90 numbers. 
     

Public Double nextdouble () a random decimal that produces a range of [0,1] , contains 0.0, and does not contain 1.0.

Note: The number placed is zero to number, but does not contain the number itself  .

There are 3 formats for 2.if statements

    1 . if  ... else  if      ...else statement is used to judge multiple conditions and handle many different kinds of processing.   
 if (conditional expression 1) {
 Execute code 1; 
}else if ( conditional expression 2  ) {
  execute code 2;   
}else{
  execute code 3;  span> 
} 
   

Execution Process: Which conditional expression is set up, executes the corresponding code,

if all the conditional expressions are not true, the body of the statement in the last else is executed

2. if The. Else statement means that if a certain condition is met, some sort of processing is performed, or another treatment is performed.

          if (conditional expression) {
             Execution Code 1;
          }else{
             Execution Code 2;
          }

If the conditional expression value is true, execute code 1

           If the conditional expression value is fales, execute code 2

               3. The If statement refers to some kind of processing if a certain condition is met.
          if (conditional expression) {
             Execute code;
          }

Execution Process: If the conditional expression value is true, the code is executed

                    If the conditional expression value is false, the code is not executed

3.for Loop, while loop, Do.....while loop

 1.
for(Condition: ①;②;③) {
    
Loop statement:④;
 The order of execution is:①==>②==>④==>③   


2.  while(condition) {

Loop statement;
Thewhile loop indicates that it is executed first, and will not be executed once if the loop condition is not satisfied. 

3.  Do{

Loop statement;

} while(conditions);

Do.. The while loop indicates that it  is executed first and then, if the loop condition is not satisfied  , at least once. 

add: The For loop applies to the number of times the loop is determined  
       While  loops anddo. . While loop   number of uncertainties

Note: The semicolon after the closing sentence;


4. Jump Control Statements 

Break ; Jump out of the loop without performing the following loop

continue; To end this loop, proceed to the following loop

Random and Scanner in Java and their looping statements