danielbunte.de – the actionscripter » Prevent using long if-expressions

Prevent using long if-expressions

6 Feb, 2009 ActionScript

Hello out there!
Today I learned how to check a lot of statements in one expression, but without having unreadable code like that:

if(this.strChar == 'a' || this.strChar == 'b' || this.strChar == 'c')
{
  .. do something ..
}

What you can do instead is creating an unnamed Array, push the values into it and then check if the Array contains one of those values.
Let’s see:

package
{
  pubilc class foo
  {
    public function foo(strChar:String = 'default'):Boolean
    {
      if(['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine', 'ten', 'default'].indexOf(strChar) >= 0)
      {
        return true;
      }
      return false;
    }
  }
}

i suppose that most of the code should be understandable to you, but let’s take a look at the if-statement:

if(['one', 'two', 'three', 'four', 'five', 'six', 'seven', 'eight', 'nine', 'ten', 'default'].indexOf(strChar) >= 0)

You could also use the following code with the same result:

var arrStringNumbers:Array = new Array();
arrStringNumbers.push('one', 'two', 'three' /*and so on... */);
 
if(arrStringNumbers.indexOf(strChar) >= 0) // give me the index of strChar (if arrStringNumbers does not contain strChar, we get -1 as result, so the if-statement is false)