15.09.29

Comparison operator SYSTEM.OUT.PRINTLN ("1! = 0 =" + (1!=0));         System.out.println ("1 > 0 =" + (1>0));         string GG = "SDSD";  String ff = "SDSD";          logical operator int BIJIAO1 = 10;          int Bijiao2 = 0;                   int Bijiao3 = 20; && Short-circuit notation: Judging from left to right, as long as there is a false, then the result will be directly output, will not continue the backward operation//logic and Operation System.out.println ("Tru         E && true = "+ (true&&true));         System.out.println ("true && false =" + (true&&false));         System.out.println ("false && false =" + (false&&false));         System.out.println ("False && false && true =" + (False && false && true)); System.out.println ("True && true && false =" + ((bijiao1>0) && (Bijiao2 = = 0) && (bijiao                  (3<0)));  //   || Short-circuit notation: Judging from left to right, as long as there is a true, then the result will be directly output, will not continue the backward operation//logic or Operation System.out.println ("true | | TruE = "+ (true | |         true)); System.out.println ("true | | false = "+ (true | |         false)); System.out.println ("false | | false = "+ (false| |         false)); System.out.println ("false | | False | | true = "+ (false| | False | |                           true));         Logical non-operational System.out.println ("!true =" +!true);               System.out.println ("!false =" +!false); Ternary operator?                  : int f = 0;                  if (age >) {f=age;                 } else {f = 0;  } System.out.println ("f =" +f);          Operator Precedence class//data type conversion int DJD = 999;                    Implicit conversion of long GJD = DJD;                    explicitly convert int djd1 = (int) Gjd;                                    Implicit conversion of float higher than long float fl = GJD;         Double db = FL;                 System.out.println ("+db");            Branch Statement--IF statement if (true)                        If the middle of the parentheses is correct, then the code inside the curly braces is executed {}//Example                  int age = 13;         if (age <) {System.out.println ("Hello, children)";         } else if (age >= && age <18) {System.out.println ("classmate, hello");         } else {System.out.println ("friend, hello");          }//Branch statement--switch statement int s = 20; Switch (s) {case://case is not supported after decimal input SYSTEM.OUT.PRI                  NTLN ("20s =" +s);                                Break Equivalent to an interrupt case 30://The constant part must be different System.out.println                 ("30s =" +s);                          Break                 Case 40:system.out.println ("40s =" +s);                          Break    Default                            Other conditions System.out.println ("other =" +s);                                       Break                                                   }

　　

15.09.29