C# 0 The Complete Reference

PART I

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PART IPART I

    // Give nums some values.

    for(int i = 0; i < 3; i++)

      for(int j=0; j < 5; j++)

        nums[i,j] = (i+1)*(j+1);

    // Use foreach to display and sum the values.

    foreach(int x in nums) {

      Console.WriteLine("Value is: " + x);

      sum += x;

    }

    Console.WriteLine("Summation: " + sum);

  }

}

The output from this program is shown here:

Value is: 1

Value is: 2

Value is: 3

Value is: 4

Value is: 5

Value is: 2

Value is: 4

Value is: 6

Value is: 8

Value is: 10

Value is: 3

Value is: 6

Value is: 9

Value is: 12

Value is: 15

Summation: 90

Since the 

foreach

 loop can only cycle through an array sequentially, from start to finish, 

you might think that its use is limited. However, this is not true. A large number of algorithms 

require exactly this mechanism, of which one of the most common is searching. For example, 

the following program uses a 

foreach

 loop to search an array for a value. It stops if the 

value is found.

// Search an array using foreach.

using System;

class Search {

  static void Main() {

    int[] nums = new int[10];

    int val;

    bool found = false;

    // Give nums some values.

    for(int i = 0; i < 10; i++)

      nums[i] = i;

    val = 5;

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    // Use foreach to search nums for key.

    foreach(int x in nums) {

      if(x == val) {

        found = true;

        break;

      }

    }

    if(found)

      Console.WriteLine("Value found!");

  }

}

The output is shown here:

Value found!

The