Linear Search
Linear search is a very simple search algorithm. In this type of search, a sequential search is made over all items one by one. Every item is checked and if a match is found then that particular item is returned, otherwise the search continues till the end of the data collection.
Here's a simple example in C#: In C#:
1 string toSearch = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
2 char[] searchArray = toSearch.ToCharArray();
3 bool found = false;
4 int i = 0;
5
6 while(found == false && i != searchArray.Length){
7 if(searchArray[i] == 'W'){
8 found = true;
9 } else {
10 i++;
11 }
12 }
13 Console.WriteLine("Found W at position: " + i);
Here's a simple example in Python 3:
1 ar = [["A", 1], ["B", 2], ["C", 3], ["D", 4], ["E", 5]];
2 ##Array to be searched
3
4 def linearSearch(arr, toFind):
5 for x in arr: ##Goes by element 1 by 1
6 if x[0] == toFind: return x[1]; ##If you find the item, return the value.
7 return None; #If you don't, return None for nothing.
8
9 print ( "Looking for 'A'", linearSearch(ar, "A") );
10 print ( "Looking for 'E'", linearSearch(ar, "E") );
11 print ( "Looking for 'l'", linearSearch(ar, "l") );
12
13 ##Return:
14 ##Looking for 'A' 1
15 ##Looking for 'E' 5
16 ##Looking for 'l' None