Main Page | See live article | Alphabetical index In computer science, values may be of first-class, second-class, or third-class: assignable passable as parameter passable as return value First-class yes yes yes Second-class yes yes no Third-class yes no no In many programming languages, labels are third-class values while numerical values are first-class values. A few languages use this kind of exact distinction. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.