fork download

copy

/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Arrays.stream(new Integer[] {12,321,312}).map(Integer::toString).forEach(System.out::println);
	}
}

Main.java:12: error: incompatible types: cannot infer type-variable(s) R
		Arrays.stream(new Integer[] {12,321,312}).map(Integer::toString).forEach(System.out::println);
		                                             ^
    (argument mismatch; invalid method reference
      reference to toString is ambiguous
        both method toString(int) in Integer and method toString() in Integer match)
  where R,T are type-variables:
    R extends Object declared in method <R>map(Function<? super T,? extends R>)
    T extends Object declared in interface Stream
Main.java:12: error: invalid method reference
		Arrays.stream(new Integer[] {12,321,312}).map(Integer::toString).forEach(System.out::println);
		                                              ^
  non-static method toString() cannot be referenced from a static context
2 errors

Standard output is empty