Checking for string contents? string Length Vs Empty String

Which is more efficient for the compiler and the best practice for checking whether a string is blank?

1. Checking whether the length of the string == 0
2. Checking whether the string is empty (strVar == "")

Also, does the answer depend on language?

Yes, it depends on language, since string storage differs between languages.

• Pascal-type strings: Length = 0.
• C-style strings: [0] == 0.
• .NET: .IsNullOrEmpty.

Etc.