Why do Java programmers like to name a variable "clazz"?

java

conventions

best-practices

readability

byNikita Barsukov·Mar 13, 2025

In Java, clazz circumvents the reserved keyword class, enabling undisrupted reference to a Class object. This is a defensive programming technique that dodges errors and ensures code clarity.

Example:

public void printClassName(Object obj) {
    Class<?> clazz = obj.getClass(); // “clazz” is the real MVP here
    System.out.println(clazz.getSimpleName());
}

The above snippet uses clazz as a surrogate for class to access and print the class name of an object, emphasizing clazz's practicality and seamless integration into Java code.

Behind the scenes: History of "clazz"

The naming convention of clazz is a historic practice stretching back to Java Development Kit (JDK) 1.0. Successive generations of Java source code and tutorials stamped clazz into Java's coding culture. Its widespread use isn't due to inherent benefits but is a legacy of convention.

From an etymological perspective

The usage of "clazz" may seem intuitive to non-native English speakers due to the familiar 's' to 'z' transition prevalent in International English. This interchangeable usage may have contributed to clazz's popularity.

Readability is king

While "Class type" provides a clear definition, the shorter clazz tends to be preferred for its brevity and unambiguous representation of a Class object.

Embracing the java tradition

Origins of "clazz” in JDK

Looking back to JDK 1.0, the clazz convention was already present in its source code. This historical usage set the foundation for future Java programmers to embrace clazz as a common practice.

Unifying code with "clazz”

Implementing clazz is key to maintaining consistency across Java codebases, as it helps increase code readability and understandability.

Alternatives to "clazz"

Notwithstanding, clazz isn't the only option. cls is also used for denoting class references, though clazz remains the community favorite.

Synthesis and implications

Practicality leads the way

Utilizing clazz is more about convenience than choice. It avers syntactic mishaps and creates a distinct identifier for a Class object.

Traditional vs contemporary usage

While adhering to conventions like clazz may seem old-fashioned, it greatly enhances code readability and comprehensibility. However, it's also worth exploring newer conventions that could shape Java's future.

Room for innovation

Should new conventions gain traction, clazz may not always be the go-to choice. Nonetheless, it currently serves its purpose flawlessly, proving that clazz is indeed in a class of its own.

explain-codes / Java / Why do Java programmers like to name a variable "clazz"?

Linked

What does .class mean in Java?



How to use Class<T> in Java?



Does Java have a "private protected" access modifier?



Why charset names are not constants?



What version of javac built my jar?

