Move more out of the for loop

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Move more out of the for loop.

using System;

public class Empty2 {
public static void Main() {
int i;

i = 0; // move initialization out of loop
for(; i < 10; ) { Console.WriteLine("Pass #" + i); i++; // increment loop control var } } } [/csharp]

Parts of the for can be empty

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Parts of the for can be empty.

using System;

public class Empty {
public static void Main() {
int i;

for(i = 0; i < 10; ) { Console.WriteLine("Pass #" + i); i++; // increment loop control var } } } [/csharp]

Loop condition can be any bool expression

   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Loop condition can be any bool expression. 
using System; 
 
public class forDemo {    
  public static void Main() {    
    int i, j; 
    bool done = false; 
 
    for(i=0, j=100; !done; i++, j--) { 
 
      if(i*i >= j) done = true; 
 
      Console.WriteLine("i, j: " + i + " " + j); 
    } 
 
  }    
}


           
          


Use commas in a for statememt to find the largest and smallest factor of a number


   

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
/* 
   Use commas in a for statememt to find 
   the largest and smallest factor of a number. 
*/ 
 
using System; 
 
public class Comma1 {    
  public static void Main() {    
    int i, j; 
    int smallest, largest; 
    int num; 
 
    num = 100; 
    
    smallest = largest = 1; 
 
    for(i=2, j=num/2; (i <= num/2) &amp; (j >= 2); i++, j--) { 
 
      if((smallest == 1) &amp; ((num % i) == 0))  
        smallest = i; 
 
      if((largest == 1) &amp; ((num % j) == 0))  
        largest = j; 
 
    } 
 
    Console.WriteLine("Largest factor: " + largest); 
    Console.WriteLine("Smallest factor: " + smallest); 
  } 
}

           
          


Use commas in a for statememt

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Use commas in a for statememt.

using System;

public class Comma {
public static void Main() {
int i, j;

for(i=0, j=10; i < j; i++, j--) Console.WriteLine("i and j: " + i + " " + j); } } [/csharp]

loop with letter char as the control variable

   
 
using System;
using System.Collections.Generic;
using System.Text;

class Program {
    static void Main(string[] args) {
        string greetingText = "www.kutayzorlu.com/java2s/com";

        for (int i = (int)&#039;z&#039;; i >= (int)&#039;a&#039;; i--) {
            char old1 = (char)i;
            char new1 = (char)(i + 1);
            greetingText = greetingText.Replace(old1, new1);
        }

        for (int i = (int)&#039;Z&#039;; i >= (int)&#039;A&#039;; i--) {
            char old1 = (char)i;
            char new1 = (char)(i + 1);
            greetingText = greetingText.Replace(old1, new1);
        }

        Console.WriteLine("Encoded:
" + greetingText);
    }
}

    


Determine if a number is prime. If it is not, then display its largest factor

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
/*
Determine if a number is prime. If it is not,
then display its largest factor.
*/

using System;

public class FindPrimes {
public static void Main() {
int num;
int i;
int factor;
bool isprime;

for(num = 2; num < 20; num++) { isprime = true; factor = 0; // see if num is evenly divisible for(i=2; i <= num/2; i++) { if((num % i) == 0) { // num is evenly divisible -- not prime isprime = false; factor = i; } } if(isprime) Console.WriteLine(num + " is prime."); else Console.WriteLine("Largest factor of " + num + " is " + factor); } } } [/csharp]