Select structure if branch structure

if Branching structure
    
     Single branch if Selection structure ：

         Grammatical structure ：
            if( Conditions ){
                // Code block
            }
         The law of execution ：
             If the condition is true, perform {} Block of code in , After executing the code block , Carry on {} Later code
             If the condition is false, Then skip if Selection structure , perform {} Later code
     Be careful ：
             No matter how simple or complex the conditions are written , The final result should be Boolean , Either for true Either for                   false

//		 establish Scanner Class object 
		Scanner sc = new Scanner(System.in);
//		 get data 
		
		System.out.println(" Zhang Hao's score is ：");
		double score =sc.nextDouble();
//		 The conditions for Zhang Hao to get the reward 
		if (score>90){
			System.out.println(" Congratulations on your success 1 Second mieba experience volume ");
			
		}
		System.out.println(" The program is finished ");
		

Double branch if-else structure ：

         Grammatical structure ：
            if( Conditions ){
                // Code block 1
            }else{
            // Code block 2 
            }
         The law of execution ：
             If the condition is true, Execute code block 1, After executing the code block 1 after , End the whole thing if-else structure , Keep going back if-else The code behind the structure
             If the condition is false, Execute code block 2, After executing the code block 2 after , End the whole thing if-else structure , Keep going back if-else The code behind the structure
    
     Be careful ：
       Conditions are Boolean

        /*
		 *  If Zhang Hao Java The test score is greater than 90 branch , The teacher rewarded him with one iPhone6s  Otherwise, the teacher will punish him for squatting 
		 */
		//  establish Scanner Class object 
				Scanner sc = new Scanner(System.in);

				System.out.println(" Please enter Zhang Hao's Java achievement ：");
				double javaScore = sc.nextDouble();

				//  Zhang Hao Java The results meet the conditions , Reward iPhone6s
				if(javaScore>90){// When conditions are met , After the execution condition {} Code inside 
					System.out.println(" Teacher reward iPhone6s");
				}else{// When conditions don't hold , perform else Back {} Code in 
					System.out.println(" do a martial-art squat ");
				}
				
				System.out.println(" The program is finished ");

Multiple branches if Select institutions

             Grammatical structure ：
                if( Conditions 1){
                    // Code block 1;
                }else if( Conditions 2){
                    // Code block 2;
                }else if( Conditions 3){
                    // Code block 3;
                }
                ....
                }else{
                     Code block n;
                }
             The law of execution ：
                 Judge the condition 1, If the condition 1 by true, Then execute the code block 1, After executing the code block 1, End the whole thing if-else-if junction                         structure , perform if-else-if The code behind the structure
                 If the condition 1 by false, Then continue to judge the conditions 2, If the condition 2 by true, Then execute the code block 2, After execution                       Code block 2, End the whole thing if-else-if structure , perform if-else-if The code behind the structure
                 If the condition 2 position false, Then continue to judge the conditions 3, If the condition 3 position true, Then execute the code block 3, After execution                       Code block 3, End the whole thing if-else-if structure , perform if-else-if The code behind the structure
                 If the condition 3 by false, Continued to ......
                 If all the conditions are not met , execute else{} Block of code in n
        
         Be careful ：
                （1） All conditions are Boolean
                （2）else if There can be many
                （3）else Yes, it can be omitted , When all conditions are not met , And there's no else When , Then the whole if-                                else-if The code in the structure will not be executed     

        /*
		 *  Evaluate the examination results of students 
		 *  achievement >=80 ： good  
		 *  achievement >=60 ： secondary 
		 *  achievement <60   ： Bad 
		 * 
		 */
	
		
		Scanner sc = new Scanner(System.in);
		System.out.println(" Please enter your score ：");
		double score = sc.nextDouble();
		
		if(score>=80){
			System.out.println(" good ");
		}else if(score>=60){
			System.out.println(" secondary ");
		}else{
			System.out.println(" Bad ");
		}
		
		System.out.println(" The program is finished ");