Day006 select structure (if statement exercise)

Catalog

1、 Use if Select the structure to judge whether an integer is even or odd .

2、 Use if Select the structure to judge whether a three digit integer is the number of daffodils .

Conditions for the number of daffodils ： Three figures are abc, Then meet ：a3+b3+c3=abc

3、 Use if Select the structure to judge whether a year is a leap year .

The conditions of leap years ：

Common leap year : Can be 4 Divide but not be 100 The year of division is a common leap year .（ Such as 2004 Year is leap year ）;

Leap year of the century : Can be 400 Divisible into century leap years .（ Such as 2000 Year is the leap year of the century ）;

 4、 Judge the grade of this exam .

 5、 Yes 3 It's an integer , Give tips ：

Can I create triangles ;

If you can build triangles , Prompt is right triangle or equilateral triangle, isosceles triangle or ordinary triangle ;

Finally, output triangle area ;

1、 Use if Select the structure to judge whether an integer is even or odd .

package cn.bdqn.Demo03;

import java.util.Scanner;

public class practice111 {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

System.out.println(" Please enter an integer ：");

int number = sc.nextInt();

System.out.println(" This integer is ："+number);

if(number%2==0){

System.out.println(" This integer is even ");

}else{

System.out.println(" This integer is odd ");

}

System.out.println(" This is the end of program execution ");

}

2、 Use if Select the structure to judge whether a three digit integer is the number of daffodils .

Conditions for the number of daffodils ： Three figures are abc, Then meet ：a3+b3+c3=abc

package cn.bdqn.Demo03;

import java.util.Scanner;

public class practice111 {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

System.out.println(" Please enter a three digit integer ：");

int number = sc.nextInt();

System.out.println(" This three digit integer is ："+number);

int geWei = number%10;

int shiWei = number/10%10;

int baiWei = number/100%10;

if(geWei*geWei*geWei+shiWei*shiWei*shiWei+baiWei*baiWei*baiWei==number){

System.out.println(" This integer is the number of daffodils ");

}else{

System.out.println(" This number is not narcissus number ");

}

System.out.println(" This is the end of program execution ");

sc.close();

}

}

 

3、 Use if Select the structure to judge whether a year is a leap year .

The conditions of leap years ：

Common leap year : Can be 4 Divide but not be 100 The year of division is a common leap year .（ Such as 2004 Year is leap year ）;

Leap year of the century : Can be 400 Divisible into century leap years .（ Such as 2000 Year is the leap year of the century ）;

package cn.bdqn.Demo03;

import java.util.Scanner;

public class practice111 {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

System.out.println(" Please enter a year ：");

int year = sc.nextInt();

if(year%4==0&&year%100!=0){

System.out.println(" This year is an ordinary leap year ");

}else if(year%400==0){

System.out.println(" This year is the year of the century ");

}else{

System.out.println(" This year is not a wet year ");

}

System.out.println(" This is the end of program execution ");

sc.close();

}

}

 4、 Judge the grade of this exam .

90-100 Between for excellent

80-89 Between is excellent

70-79 Between for good ,

60-69 Between for pass

60 Below is a failing grade .

package cn.bdqn.Demo03;

import java.util.Scanner;

public class practice111 {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

System.out.println(" Please enter the test scores ：");

int grade = sc.nextInt();

System.out.println(" The test result is ："+grade);

if(grade>=90&&grade<=100){

System.out.println(" good ");

}else if(grade>=80){

System.out.println(" excellent ");

}else if(grade>=70){

System.out.println(" good ");

}else if(grade>=60){

System.out.println(" pass ");

}else{

System.out.println(" fail, ");

}

System.out.println(" This is the end of program execution ");

sc.close();

}

}

 

 5、 Yes 3 It's an integer , Give tips ：

Can I create triangles ;

If you can build triangles , Prompt is right triangle or equilateral triangle, isosceles triangle or ordinary triangle ;

Finally, output triangle area ;

package cn.bdqn.Demo03;

import java.util.Scanner;

public class practice111 {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

System.out.println(" Please enter three integers ：");

int a = sc.nextInt();

int b = sc.nextInt();

int c = sc.nextInt();

double q=(a+b+c)/2.0;

double s=q*(q-a)*(q-b)*(q-c);

System.out.println(Math.sqrt(s));

if((a+b>c)||(a+c>b)||(b+c>a)){

if((a>b&&a>c&&b*b+c*c==a*a)||(b>a&&b>c&&c*c+a*a==b*b)||(c>a&&c>b&&a*a+b*b==c*c)){

System.out.println(" right triangle ");

//System.out.println(s);

}

else if(a==b&&a==c){

System.out.println(" Equilateral triangle ");

//System.out.println(s);

}

else if(a==b||a==c||b==c){

System.out.println(" an isosceles triangle ");

//System.out.println(s);

}else if((a+b<c)||(a+c<b)||(b+c<a)){

System.out.println(" Cannot build triangles ");

}

}else{

System.out.println(" Ordinary triangle ");

//System.out.println(s);

}

System.out.println(" This is the end of program execution ");

sc.close();

}

}

 

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