Foundations

Arrays

Arrays keep related values in order and let code read them by index.

array index Array indexes start at zero, so `scores[0]` reads the first value.

Arrays

bonus
Arrays.cs
Replay: real traced execution (multi-file project)
using System;

class Program
{
    static void Main()
    {
        int[] scores = { 82, 91, 76 };
        int bonus = 5;
        int firstScore = scores[0];
        int adjustedScore = scores[1] + bonus;

        Console.WriteLine($"first={firstScore}");
        Console.WriteLine($"adjusted={adjustedScore}");
    }
}

using System;

class Program
{
    static void Main()
    {
        int[] scores = { 82, 91, 76 };
        int bonus = 0;
        int firstScore = scores[0];
        int adjustedScore = scores[1] + bonus;

        Console.WriteLine($"first={firstScore}");
        Console.WriteLine($"adjusted={adjustedScore}");
    }
}

using System;

class Program
{
    static void Main()
    {
        int[] scores = { 82, 91, 76 };
        int bonus = 10;
        int firstScore = scores[0];
        int adjustedScore = scores[1] + bonus;

        Console.WriteLine($"first={firstScore}");
        Console.WriteLine($"adjusted={adjustedScore}");
    }
}

  1. bonus ← 5, firstScore ← 82, adjustedScore ← 96

    4{5    static void Main()6    {7        int[] scores = { 82, 91, 76 };8        int bonus→ 5 = 5; //@bonus=0, 109        int firstScore→ 82 = scores[0]82;10        int adjustedScore→ 96 = scores[1]91 + bonus5;1112        Console.WriteLine($"first={firstScore82}");13        Console.WriteLine($"adjusted={adjustedScore96}");14    }
    outputfirst=82
adjusted=96

  1. bonus ← 0, firstScore ← 82, adjustedScore ← 91

    4{5    static void Main()6    {7        int[] scores = { 82, 91, 76 };8        int bonus→ 0 = 0;9        int firstScore→ 82 = scores[0]82;10        int adjustedScore→ 91 = scores[1]91 + bonus0;1112        Console.WriteLine($"first={firstScore82}");13        Console.WriteLine($"adjusted={adjustedScore91}");14    }
    outputfirst=82
adjusted=91

  1. bonus ← 10, firstScore ← 82, adjustedScore ← 101

    4{5    static void Main()6    {7        int[] scores = { 82, 91, 76 };8        int bonus→ 10 = 10;9        int firstScore→ 82 = scores[0]82;10        int adjustedScore→ 101 = scores[1]91 + bonus10;1112        Console.WriteLine($"first={firstScore82}");13        Console.WriteLine($"adjusted={adjustedScore101}");14    }
    outputfirst=82
adjusted=101

Follow the Array

  1. scores starts as 82, 91, and 76.
  2. bonus starts at 5.
  3. firstScore reads 82.
  4. adjustedScore adds 91 + 5.
  5. The program prints first=82 and adjusted=96. | bonus | firstScore | adjustedScore | | --- | --- | --- | | 0 | 82 | 91 | | 5 | 82 | 96 | | 10 | 82 | 101 |

Exercise: Arrays.cs

Reproduce first=82 and adjusted=96, then use the pinned bonuses 0 and 10 to predict each adjusted score.