With this example we are going to demonstrate how to use conflicting constructors in a class. In short, to use conflicting constructors in a class we have followed the steps below:
- We have created a class
ConflictingConstructors, that has a constructor without fields and a constructor that gets an int value and throws an IllegalArgumentException if it is smaller than0. It also has avoid Constructor()method and another method,method1(). - We create a new instance of
ConflictingConstructors, using its first constructor and then call itsmethod1()method. - We also call its
Constructor()method. - We create a new instance of the class, using its second constructor with a value smaller than zero to see that the exception is now thrown.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
public class ConflictingConstructors {
/**
* Constructor
*/
public ConflictingConstructors() {
System.out.println("In the constructor");
}
/**
* Constructor that throws
*/
public ConflictingConstructors(int value) {
if (value < 0) {
throw new IllegalArgumentException("Constructors: value < 0");
}
}
/**
* Not a Constructor, because of void
*/
public void Constructors() { // EXPECT COMPILE ERROR some compilers
System.out.println("In void Constructor()");
}
void method1() {
for (int i = 0; i < 5; i++) {
System.out.println(i);
}
}
public static void main(String[] a) {
ConflictingConstructors l = new ConflictingConstructors();
l.method1();
l.Constructors();
new ConflictingConstructors(-1); // expect Exception
}
}
Output:
In the constructor
0
1
Exception in thread "main" java.lang.IllegalArgumentException: Constructors: value < 0
2
3
4
In void Constructor()
at methodoverloading.ConflictingConstructors.<init>(ConflictingConstructors.java:17)
at methodoverloading.ConflictingConstructors.main(ConflictingConstructors.java:38)
Java Result: 1
This was an example of how to use conflicting constructors in a class in Java.
