C # for/foreach loop
One for loop is a repetitive control structure that allows you to writea loop that executes a specific number of times.
Grammar
In C # for syntax of the loop:
for ( init; condition; increment )
{
statement(s);
}
The following is for control flow of the loop:
initwill be executed first, and only once. This step allows you to declare and initialize any loop control variables. You can also not write any statements here, as long as a semicolon appears.Next, it will judge
condition. If true, the loop body is executed. If false, the loop body is not executed, and the control flow jumps to the followingforstatement of the loop.After the execution
forafter looping the body, the control flow jumps back to theincrementstatement. This statement allows you to update loop control variables. This statement can be left blank as long as a semicolon appears after the condition.The conditions are judged again. If true, the loop is executed, and the process is repeated over and over again (loop body, then increase the step value, and then re-determine the condition). When the condition becomes false
forcycle ends.
Flow chart
Example
using System;
namespace Loops
{
class Program
{
static void Main(string[] args)
{
/* for loop execution */
for (int a = 10; a < 20; a = a + 1)
{
Console.WriteLine("Value of a： {0}", a);
}
Console.ReadLine();
}
}
}
When the above code is compiled and executed, it produces the following results:
Value of a: 10
Value of a: 11
Value of a: 12
Value of a: 13
Value of a: 14
Value of a: 15
Value of a: 16
Value of a: 17
Value of a: 18
Value of a: 19
Foreach
C # also supports foreach looping, use foreach, you can iterate through an array or a collection object.
The following example has three parts:
Pass through
foreachloop outputs elements in an integer array.Pass through
forloop outputs elements in an integer array.foreachloops to set the calculator for array elements.
class ForEachTest
{
static void Main(string[] args)
{
int[] fibarray = new int[] { 0, 1, 1, 2, 3, 5, 8, 13 };
foreach (int element in fibarray)
{
System.Console.WriteLine(element);
}
System.Console.WriteLine();
// Similar to foreach loop
for (int i = 0; i < fibarray.Length; i++)
{
System.Console.WriteLine(fibarray[i]);
}
System.Console.WriteLine();
// Set the calculator for elements in the collection
int count = 0;
foreach (int element in fibarray)
{
count += 1;
System.Console.WriteLine("Element #{0}: {1}", count, element);
}
System.Console.WriteLine("Number of elements in the array: {0}", count);
}
}
The output is as follows:
0
1
1
2
3
5
8
13
0
1
1
2
3
5
8
13
Element #1: 0
Element #2: 1
Element #3: 1
Element #4: 2
Element #5: 3
Element #6: 5
Element #7: 8
Element #8: 13
Number of elements in the array: 8