Most effiecient way to compare a string and an Array [closed]

Question

I want to compare a string and an array like this,

    string str1 = "Ceo, Hr, Coo, Mccal";
    string[] str2 = new string[] {"CEO", "COO", "HR", "McCal","CSU","PSU"};

I want to check if str2 has a value of str1, checking one value at a time, like Ceo, then Hr, then Coo etc. If there is a match, I want the str2 value, like looking up Ceo should return me CEO.

What is the most efficient way to do it without looping? I have to compare multiple strings to str2.

Answer 1

You didn't specify a language, so I'll write in Java. You should be able to do the equivalent just as easily.

Java has the String.split() function, which could be used on ", " to give you a string array. From there, the problem is a variation of determining if a string is in multiple arrays. Personally, I like using a HashSet for that functionality, although there are a number of ways to do it.

Just a quick code sketch:

HashSet<String> str2Set = new HashSet<String>();
for(String s : str2)
    str2Set.add(s);

String[] splitStr1 = str1.split(", ");

for(String s : splitStr1)
   //toUpperCase may not be necessary outside example depending on your data
   if(str2Set.contains(s.toUpperCase())
      return s.toUpperCase();

EDIT 1:

C# string split:

Regex(", ").Split(str1);