C++ Lesson 3

 Learning Objectives

1.      Arithmetic expression

2.      Conditional statements

 

 

Exercise 3-1

#include <iostream>

using namespace std;

int main() {

  cout<<5+2;

  cout<<5-2; 

  cout<<5*2;

  cout<<5/2;

  cout<<5%2;

return 0;

}

 

<<Assignment 3-1>>

 

<<Assignment 3-2>>

 

Exercise 3-2

#include <iostream>

using namespace std;

int main() {

int a;

cout<<"enter a number smaller than 10:";

cin>>a;

if (a<=10){

    cout<<a<<" is smaller than 10";

}

return 0;

}

 

Exercise 3-3

#include <iostream>

using namespace std;

int main() {

int a;

cout<<"enter a number: ";

cin>>a;

if (a<=10){

    cout<<a<<" is smaller than 10";

}

else{

    cout<<a<<" is greater than 10";

}

return 0;

}

 

Exercise 3-4

#include <iostream>

using namespace std;

int main() {

int a;

cout<<"enter a number: ";

cin>>a;

if (a%3>0){

    cout<<a<<" cannot be divided by 3";

}

else{

    cout<<a<<" can be divided by 3";

}

 

return 0;

}

Exercise 3-5

#include <iostream>

using namespace std;

int main() {

int a;

cout<<"enter a number: ";

cin>>a;

if (a%3>0)

    cout<<a<<" cannot be divided by 3";

else

    cout<<a<<" can be divided by 3";

return 0;

}

 

<<Assignment 3-3>>

Enter a mark. If the mark is over 60, output “passed”. If the mark is below 60, output “failed”.

 

<<Assignment 3-4>>

Enter a number within 50, and distinguish whether it is a prime number(質數)

The output is as follow:

提示: 質數是除了1及自己之外，不能被其他數字整除的數字。