Alternative to if, else if

Question

I have a lot of if, else if statements and I know there has to be a better way to do this but even after searching stackoverflow I\'m unsure of how to do so in my particular cas

Answer 1

One way of doing it (other answers show very valid options):

void Main()
{
    string input = "georgiapower.com";
    string output = null;

    // an array of string arrays...an array of Tuples would also work, 
    // or a List<T> with any two-member type, etc.
    var search = new []{
        new []{ "SWGAS.COM", "Southwest Gas"},
        new []{ "georgiapower.com", "Georgia Power"},
        new []{ "City of Austin", "City of Austin"}
    };

    for( int i = 0; i < search.Length; i++ ){

        // more complex search logic could go here (e.g. a regex)
        if( input.IndexOf( search[i][0] ) > -1 ){
            output = search[i][1];
            break;
        }
    }

    // (optional) check that a valid result was found.
    if( output == null ){
        throw new InvalidOperationException( "A match was not found." );
    }

    // Assign the result, output it, etc.
    Console.WriteLine( output );
}

The main thing to take out of this exercise is that creating a giant switch or if/else structure is not the best way to do it.

Answer 2

There are several approaches to do this, but for the reason of simplicity, conditional operator may be a choice:

Func<String, bool> contains=x => {
    return txtvar.BillText.IndexOf(x)>-1;
};

txtvar.Provider=
    contains("SWGAS.COM")?"Southwest Gas":
    contains("georgiapower.com")?"Georgia Power":
    contains("City of Austin")?"City of Austin":
    // more statements go here 
    // if none of these matched, txtvar.Provider is assigned to itself
    txtvar.Provider;

Note the result is according to the more preceded condition which is met, so if txtvar.BillText="City of Austin georgiapower.com"; then the result would be "Georgia Power".