Loop condition can be any bool expression. : For « Statement « C# / CSharp Tutorial

using System; 
 
class MainClass {    
  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); 
    } 
 
  } 
}

i, j: 0 100
i, j: 1 99
i, j: 2 98
i, j: 3 97
i, j: 4 96
i, j: 5 95
i, j: 6 94
i, j: 7 93
i, j: 8 92
i, j: 9 91
i, j: 10 90

4.3.For
	4.3.1.	for loop
	4.3.2.	Demonstrate a block of code inside if statement
	4.3.3.	Use block inside for statement: Compute the sum and product of the numbers from 1 to 10
	4.3.4.	Use byte to control for loop
	4.3.5.	A negatively running for loop
	4.3.6.	Nested for loop to calculate prime number
	4.3.7.	Use commas in a for statement.
	4.3.8.	Use commas in a for statement to find the largest and smallest factor of a number
	4.3.9.	Loop condition can be any bool expression.
	4.3.10.	Parts of the for can be empty.
	4.3.11.	Move 'update' out of the for loop
	4.3.12.	For loop with multiple expressions
	4.3.13.	The body of a loop can be empty
	4.3.14.	Declare loop control variable inside the for
	4.3.15.	Using break to exit a for loop