Improved techniques for representation of Java data types in virtual machines are disclosed. The techniques can be implemented to represent signatures of Java methods as arrays of references. Each of the references in an array can represent a parameter for a Java method. Accordingly, a signature can be represented as an array of references, wherein each reference in the array can reference a Java type indicator or an internal class representation. The Java type indicator represents a Java primitive type (e.g., byte, integer, double, etc.) The internal class representation is typically the representation of a Java class as represented in a virtual machine. As will be appreciated, an array organization allows for more efficient access to information. Thus, unlike conventional techniques, there is no need to start at the beginning of the signature and sequentially read it to find a particular parameter's data type. In addition, the internal class representations can be accessed directly from the method signature representation. This allows for quick access to the internal class representations from the signature, therefore, less processing is needed to execute methods. As a result, the performance of virtual machines, especially those operating with limited resources, can be improved.