Sumy

/* Suma1.java

Program wyznacza sumę liczb, suma = 1 + 2 + 3.
*/

public class Suma1
{
  public static void main(String[] args)
  {
    int suma = 0;
    int i = 1;
    
    suma = suma + i; // suma = 0 + 1 = 1
    i++; // i = 2
    
    suma = suma + i; // suma = 1 + 2 = 3
    i++; // i = 3
    
    suma = suma + i; // suma = 3 + 3 = 6
    i++; // i = 4
    
    System.out.println("suma = " + suma);
    System.out.println("i = " + i);
  }
}

suma = 6
i = 4
Press any key to continue...

/* Suma2.java

Program wyznacza sumę liczb,  suma = 1 + 2 + ... + n, gdzie n = 3.
*/

public class Suma2
{
  public static void main(String[] args)
  {
    int n = 3;
    int suma = 0;
    int i;
    
    for (i = 1; i <= n; i++)
    {
      suma = suma + i;
    }
    
    System.out.println("suma = " + suma);
    System.out.println("i = " + i);
  }
}

suma = 6
i = 4
Press any key to continue...

n = 3
suma = 0
i

i = 1
1 <= 3   suma = 0 + 1 = 1   i = 2
2 <= 3   suma = 1 + 2 = 3   i = 3
3 <= 3   suma = 3 + 3 = 6   i = 4
4 <= 3   false

"suma = 6"
"i = 4"

Strona główna