The isVarArgs() method of java.lang.reflect.Constructor class is used to return the boolean value true if this Constructor can take a variable number of arguments as parameters else method will return false.VarArgs allows the constructor to accept a number of arguments. using VarArgs is a better approach to pass arguments than array when it is not known how many arguments to pass in the constructor.
Syntax:
public boolean isVarArgs()
Parameters: This method accepts nothing.
Return: This method returns true if and only if this executable was declared to take a variable number of arguments.
Below programs illustrate isVarArgs() method:
Program 1:
Java
// Java program to illustrate isVarArgs() methodimport java.lang.annotation.Annotation;import java.lang.reflect.Constructor;public class GFG { public static void main(String[] args) { // create a class object Class classObj = shape.class; // get Constructor object // array from class object Constructor[] cons = classObj.getConstructors(); // check isVarArgs or not boolean isVargs = cons[0].isVarArgs(); // print result System.out.println("isVargs : " + isVargs); } public class shape { public shape(Object... objects) { } }} |
isVargs : true
Program 2:
Java
// Java program to illustrate isVarArgs() methodimport java.lang.annotation.Annotation;import java.lang.reflect.Constructor;public class GFG { public static void main(String[] args) { // create a class object Class classObj = String.class; // get Constructor object // array from class object Constructor[] cons = classObj.getConstructors(); for (int i = 0; i < cons.length; i++) { // check isVarArgs or not boolean isVargs = cons[i].isVarArgs(); // print result System.out.println(cons[i]); System.out.println("isVargs : " + isVargs); } }} |
public java.lang.String(byte[], int, int) isVargs : false public java.lang.String(byte[], java.nio.charset.Charset) isVargs : false public java.lang.String(byte[], java.lang.String) throws java.io.UnsupportedEncodingException isVargs : false public java.lang.String(byte[], int, int, java.nio.charset.Charset) isVargs : false public java.lang.String(byte[], int, int, java.lang.String) throws java.io.UnsupportedEncodingException isVargs : false public java.lang.String(java.lang.StringBuilder) isVargs : false public java.lang.String(java.lang.StringBuffer) isVargs : false public java.lang.String(byte[]) isVargs : false public java.lang.String(int[], int, int) isVargs : false public java.lang.String() isVargs : false public java.lang.String(char[]) isVargs : false public java.lang.String(java.lang.String) isVargs : false public java.lang.String(char[], int, int) isVargs : false public java.lang.String(byte[], int) isVargs : false public java.lang.String(byte[], int, int, int) isVargs : false
References: https://docs.oracle.com/javase/10/docs/api/java/lang/reflect/Constructor.html#isVarArgs()
