Linear Search Exercice

Linear search

Solution with while loop

string[] persons = ["Juliana", "Logan", "Gabriela", "Valentina", "Lelio", "Linda"];


Console.Write("Name => ");
string name = Console.ReadLine();
int position = 0;

while (position < persons.Length && name != persons[position])
{
    position++;
}

if (position == persons.Length)
{
    Console.WriteLine($"Not found: no name like '{name}'.");
}
else
{
    Console.WriteLine($"Found! Position is {position}.");
}

Solution with for loop

string[] persons = ["Juliana", "Logan", "Gabriela", "Valentina", "Lelio", "Linda"];

Console.Write("Insert a name:");
string name = Console.ReadLine();

int position;
bool found = false;

for (position = 0; position < persons.Length; position++)
{
    if (persons[position] == name)
    {
        found = true;
        break;
    }
}

if (found == false)
{
    Console.WriteLine("Not found!");

}
else
{
    Console.WriteLine($"Found! position is {position}");
}

Note

Exercise: Find Valentina

INPUT    What do I receive?        Valentina
OUTPUT   What do I give back?      Position (index)
EXAMPLE  Solve one by hand:        Valentina => 3

STEPS    In plain words, no C#:
  1. Ask for a name
  2. Define starting position at zero
  3. Compare given name to name at current position
  4. If given is the same as current position then step and show position
  5. If not the same then we go to the next position
  6. Compare again
  3. I stop when I find a match
  4. Show the position

TRACE
  | turn | Name      | ........ |
  |    0 | Juliana   |          |
  |    1 | Logan     |          |
  |    2 | Gabriela  |          |
  |    3 | Valentina |          |

EDGE CASES  0? 1? negative? empty?  ......................