Day06 branch structure and cycle (III)

1.continue keyword

continue ： continue

Applicable scenario ： It can only be used in a cycle

effect : Jump out of this cycle , Continue with next cycle

break and continue The difference between ？

Different scenarios ,break It can be used for switch And the cycle ,continue It can only be used in a cycle

The effect is different ：

break Indicates an interrupt loop , The number of cycles that have not been executed is no longer executed

continue Jump out of this cycle , Continue with next cycle

package com.qfedu.test1;
/**
 * 	continue ： continue 
 * 	 Applicable scenario ： It can only be used in a cycle 
 * 	 effect : Jump out of this cycle , Continue with next cycle 
 * 
 * 	break and continue The difference between ？
 * 	 Different scenarios ,break It can be used for switch And the cycle ,continue It can only be used in a cycle 
 * 	 The effect is different ：
 * 		break Indicates an interrupt loop , The number of cycles that have not been executed is no longer executed 
 * 		continue Jump out of this cycle , Continue with next cycle 
 * @author WHD
 *
 */
public class Test1 {
	public static void main(String[] args) {
		//  apply for Loop printing 1 ~ 10   When i The values for 5   Separate use break and continue  See the effect 
		for (int i = 1; i <= 10; i++) {
			if(i == 5) {
				continue;
			}
			System.out.println(i);
		}
	}
}

package com.qfedu.test1;

import java.util.Scanner;

/**
 * 	 Cycle input Java Students' grades in class , The statistical score is greater than or equal to 80 The proportion of students who get a score 
 * @author WHD
 *
 */
public class Test2 {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		
		System.out.println(" Please enter the number of people ");
		
		int num = input.nextInt();
		
		double count = 0;
		
		for(int i = 1;i <= num;i++) {
			System.out.println(" Please enter the first "+ i +" Personal achievements ");
			
			int score = input.nextInt();
			
			if(score < 80) {
				System.out.println(" The score is less than 80 branch , There is no need to accumulate ");
				continue;
			}
			
			count++;//  The code can be executed to this step   Indicates that the score is greater than or equal to 80 Points of   Because if it's less than 80 branch   Will perform continue continue Subsequent code   No more execution 
			
		}
		
		
		System.out.println(" Greater than or equal to 80 The proportion of the number of points is " + count / num * 100 + "%");
		
		
		
	}
}

package com.qfedu.test1;
/**
 * 	while Circulation and do-while Use in loop continue
 * @author WHD
 *
 */
public class Test3 {
	public static void main(String[] args) {
		int i = 0;
		while(i <= 10) {
			
			i++;
			if(i == 5) {
				continue;
			}
			System.out.println(i);
			
		}
		
		System.out.println("====================================");
		
		int j = 0;
		do {
			j++;
			if(j == 5) {
				continue;
			}
			System.out.println(j);
			
		}while(j <= 10);
		
		
		
	}
}

package com.qfedu.test1;
/**
 * 	 seek 1~10 Between all even numbers and 
 * @author WHD
 *
 */
public class Test4 {
	public static void main(String[] args) {
		int sum = 0;
		for (int i = 1; i <= 10; i++) {
			if(i % 2 != 0) {
				continue;
			}
			sum += i;
		}
		System.out.println(sum);
		
		System.out.println("===========================================");
		
		int sum1 = 0;
		
		for(int i = 0;i <= 10;i+=2) {
			sum1 += i;
		}
		
		System.out.println(sum1);
		
		
	}
}

3. Double cycle

The outer variable changes once The inner circulation variable changes one round

The outer loop controls the number of lines

The number of inner loop control columns

The number of elements in the first line determines the initial value of the counter ,

More and more elements , Just ++, When counter ++ When , We have to set an upper limit , That is, our condition must be less than or equal to a certain value ,

Otherwise it's a dead cycle

Fewer and fewer elements , Just --, When counter -- When , We have to set a lower limit , That is, our condition must be greater than or equal to a certain value ,

Otherwise it's a dead cycle

package com.qfedu.test3;
/**
 * 	 parallelogram 
 * 	 When we use multiple loops to print triangles ：
 * 	 The number of elements in the first line determines the initial value of the counter ,
 * 	 More and more elements , Just ++, When counter ++ When , We have to set an upper limit , That is, our condition must be less than or equal to a certain value ,
 * 	 Otherwise it's a dead cycle 
 * 	 Fewer and fewer elements , Just --, When counter -- When , We have to set a lower limit , That is, our condition must be greater than or equal to a certain value ,
 * 	 Otherwise it's a dead cycle 
 * @author WHD
 *
 */
public class Test2 {
	public static void main(String[] args) {
		for (int i = 1; i <= 5; i++) { //  Number of lines   5 That's ok   perform 5 The second outer cycle 
			//  The left half   Inverted triangle 
			for(int j = 5;j >= i;j--) {
				System.out.print("&");
			}
			
			
			//  The right half   rectangular 
			for(int j = 1;j <= 5;j++) {
				System.out.print("*");
			}
			
			//  Line break 
			System.out.println();
		}
	}
}

package com.qfedu.test4;
/**
 * 	 Print equilateral triangles using multiple loops 
 * 
 * 	 The outer loop controls the number of lines 
 * 	 The number of inner loop control columns 
 * 
 * 	 The number of elements in the first line determines the initial value of the counter ,
 * 	 More and more elements , Just ++, When counter ++ When , We have to set an upper limit , That is, our condition must be less than or equal to a certain value ,
 * 	 Otherwise it's a dead cycle 
 * 	 Fewer and fewer elements , Just --, When counter -- When , We have to set a lower limit , That is, our condition must be greater than or equal to a certain value ,
 * 	 Otherwise it's a dead cycle 
 * @author WHD
 *
 */
public class Test1 {
	public static void main(String[] args) {
		for (int i = 1; i <= 5; i++) { // 5 Row pattern 
			//  The left half   Inverted triangle 
			for(int j = 5;j >= i ;j--) {
				System.out.print("^");
			}
			
			//  The right half   right triangle   Because the shape of the left half    Squeeze the right side into an equilateral triangle 
			for(int j = 1;j <= i * 2 -1 ;j++) {
				System.out.print("*");
			}
			
			//  Line break 
			System.out.println();
		}
	}
}

package com.qfedu.test4;

import java.util.Scanner;

/**
 * 	 Use the multi loop print bank menu system 
 * @author WHD
 *
 */
public class Test4 {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int choice = 0;
		do {
			System.out.println("***********************************************");
			System.out.println("************* Welcome to use ATM Bank menu system *************");
			System.out.println("1. Accounts   2. deposit   3. Withdraw money   4. The loan   5. Change Password   6. Check the balance   0. sign out ");
			System.out.println("***********************************************");
			choice = input.nextInt();
			switch (choice) {
			case 1:
				System.out.println(" Perform account opening function ");
				break;
			case 2:
				System.out.println(" Execute the deposit function ");
				break;
			case 3:
				System.out.println(" Perform the withdrawal function ");
				break;
			case 4:
				System.out.println(" Perform the loan function ");
				break;
			case 5:
				System.out.println(" Perform the password modification function ");
				break;
			case 6:
				System.out.println(" Execute the function of querying balance ");
				break;
			case 0:
				System.out.println(" sign out , Welcome to use next time ~");
				break;
			default:
				System.out.println(" Incorrect input , Please re-enter ");
				break;
			}
		} while (choice != 0);
		System.out.println(" Program end ");
	}
}

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