Home  >  Article  >  Java  >  How to Identify Primitive Values in an Object[] Array?

How to Identify Primitive Values in an Object[] Array?

DDD
DDDOriginal
2024-11-03 10:25:29851browse

How to Identify Primitive Values in an Object[] Array?

Determining if an Object is Primitive

Question:
When dealing with an Object[] array, how can you identify which elements represent primitive values? Using Class.isPrimitive() appears to yield incorrect results.

Answer:
Understanding that the elements in an Object[] array are references to objects, it becomes clear that Class.isPrimitive() will always return false. To determine if an object is a "wrapper for primitive" (e.g., Integer for int), a custom approach is necessary.

Here's a Java code snippet that demonstrates a solution:

<code class="java">import java.util.*;

public class Test {

    public static void main(String[] args) {
        System.out.println(isWrapperType(String.class)); // false
        System.out.println(isWrapperType(Integer.class)); // true
    }

    private static final Set<Class<?>> WRAPPER_TYPES = getWrapperTypes();

    public static boolean isWrapperType(Class<?> clazz) {
        return WRAPPER_TYPES.contains(clazz);
    }

    private static Set<Class<?>> getWrapperTypes() {
        Set<Class<?>> ret = new HashSet<>();
        ret.add(Boolean.class);
        ret.add(Character.class);
        ret.add(Byte.class);
        ret.add(Short.class);
        ret.add(Integer.class);
        ret.add(Long.class);
        ret.add(Float.class);
        ret.add(Double.class);
        ret.add(Void.class);
        return ret;
    }
}</code>

By utilizing this approach, you can accurately determine whether an object in an Object[] array represents a primitive value or a wrapper class for a primitive value.

The above is the detailed content of How to Identify Primitive Values in an Object[] Array?. For more information, please follow other related articles on the PHP Chinese website!

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn