Javase Review Diary: Conditional judgment statement

/*                              Conditional Control statement: if () {}else{} syntax: First structure: There is no execution if (Boolean expression) {//First                Bit true, the execution of the inside of the statement, for false will not execute the Java statement;                The second structure: if (Boolean expression) {Java statement;                }else{Java statements;                The third structure: multiple conditional discriminant, with non-executable if (Boolean expression) {Java statement;                }else if (Boolean expression) {Java statement;                }else if (Boolean expression) {Java statement;                }else if (Boolean expression) {Java statement;                The fourth structure: Overwrite all cases if (Boolean expression) {Java statement;                }else if (Boolean expression) {Java statement;                }else if (Boolean expression) {Java statement;                }else if (Boolean expression) {Java statement;            }else{Java statements;    Note: The entire if statement ends if there is only one branch executing in the IF statement.              The above structure 2, 4, can guarantee that there will be a branch statement execution, because they all have an else statement.  The following example:*//*Public class javase{public static void Main (string[] args) {Boolean a = true;             if (a) {///If A is true, the following statement is output;         SYSTEM.OUT.PRINTLN ("Login Successful");             }else{//If A is false, the following statement is output;         SYSTEM.OUT.PRINTLN ("Login Failed"); }     } } *///there is a slightly more complicated case://the division of an Age (1~100岁) is defined as follows://[1-5] Toddlers//[6-18] Juvenile//[19-35] Youth//[36-55] Middle-aged//[56-100] old age////now a 54-year-old person, asked to write a code to determine the age of the person, and output the results;/*Public class javase{public static void Main (string[] args) {int = 54;//declaration variable, one person's age is 54 years old if (age&        Gt;=1 && age<=5) {System.out.println ("This person is a child");        }else if (age<=18) {System.out.println ("This person is a teenager");        }else if (age<=35) {System.out.println ("This person is a youth");        }else if (age<=55) {System.out.println ("This person is middle-aged");        }else if (age<=100) {System.out.println ("This person is old age"); }            }}*//** Conditional CONTROL Statement while * * * switch (int type) {//inside can only be Int/byte/short/char type, because can be self- //javase7, can be a string type * case INT type: * Execute the statement, and cannot be a long integer type, double type, Boolean type, etc. * * EXECUTE statement; * BREAK; * Case INT Type: * EXECUTE statement; * EXECUTE statement; * BREAK; * Case INT Type: * EXECUTE statement; * EXECUTE statement; * BREAK; * Case INT Type: * EXECUTE statement; * EXECUTE statement;      * BREAK; Can not * Default: * EXECUTE statement; Can not have a *} * break statement If there is no case statement penetrating phenomenon **/ Public classjavase{ Public Static voidmain (String [] args) {inti = (int)'in';//Forcing type conversionsSystem. out. println (i); CharC_0 = (Char) the; System. out. println (C_0); //Character Type        Charc ='B'; //char c = ' F ';        Switch(c) { Case 'A': System. out. println ("Excellent");  Break;  Case 'B': System. out. println ("Excellent");  Break;  Case 'C': System. out. println ("General");  Break; default: System. out. println ("Poor"); }        //Case Merge:        Charc_02 ='D'; Switch(c_02) { Case 'A': Case 'B': Case'C'://Merge, if ABC has output the following ' excellent ', then stop here (break), otherwise ready to run down;System. out. println ("Excellent");  Break;  Case 'D': System. out. println ("General");  Break; default: System. out. println ("General"); }    }}

Javase Review Diary: Conditional judgment statement