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for

The for loop executes a statement or a block of statements repeatedly until a specified expression evaluates to false. It takes the following form:

for ([initializers]; [expression]; [iterators]) statement

where:

initializers
A comma separated list of expressions or assignment statements to initialize the loop counters.
expression
An expression that can be implicitly converted to bool or a type that contains overloading of the true and false operators. The expression is used to test the loop-termination criteria.
iterators
Expression statement(s) to increment or decrement the loop counters.
statement
The embedded statement(s) to executed.

Remarks

The for statement executes the statement repeatedly as follows:

  • First, the initializers are evaluated.
  • Then, while the expression evaluates to true, the statement(s) are executed and the iterators are evaluated.
  • When the expression becomes false, control is transferred outside the loop.

Because the test of expression takes place before the execution of the loop, a for statement executes zero or more times.

All of the expressions of the for statement are optional; for example, the following statement is used to write an infinite loop:

for (;;) {
   ...
}

Example

// statements_for.cs
// for loop
using System;
public class ForLoopTest 
{
   public static void Main() 
   {
      for (int i = 1; i <= 5; i++) 
         Console.WriteLine(i);
   }
}

Output

1
2
3
4
5

See Also

C# Keywords | Compare to C++ | Iteration Statements | C. Grammar

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