Setter

In short: A setter is a method that sets the value of a private attribute, usually with a check.

In more detail: It follows the naming rule setAttribute(value).

In Depth

private int age;
public void setAge(int age) {
    if (age < 0) throw new IllegalArgumentException("negative");
    this.age = age;
}

The check protects against invalid states. See getter, this, private.

See also: Getter, Meaning of this, private