用方法参数找到数组最小值的优雅方法？

Question

I'm looking for an elegant way to express this pseudo code. For my assignment, I cannot change the method signature or parameter type.

    private static int smallest(int... nums)
    {
        return Arrays.stream(nums).min().getAsInt();
    }

All I'm trying to do is take a huge varying list of ints as a parameter from the method call and return the smallest int of all the int parameters. I've tried to google and read the API to find out how to correctly implement this, but I've gotten only this far. Can someone help me syntactically correct this to compile and output correctly?

I cannot correctly post my console errors with formatting, so I'm posting it as an update to my OP. To answer @Marvin I'm getting this error in my compiler...

Methods1.java:25: error: cannot find symbol
  int small = Arrays.stream(nums).min().getAsInt();
              ^
symbol:   variable Arrays
location: class Methods1
1 error

Answer 1

You almost had it, it's getAsInt() instead of get() :

private static int smallest(int... nums) {
    return Arrays.stream(nums).min().getAsInt();
}

Complete working sample on ideone.com :

import java.util.Arrays;

class Ideone {
    public static void main (String[] args) {
        int[] nums = new int[] { 7, -2, 5, 12 };
        System.out.println(smallest(nums));
    }

    private static int smallest(int... nums) {
        return Arrays.stream(nums).min().getAsInt();
    }
}

Prints:

-2

Answer 2

You could iterate over the whole array like this

private static int smallest(int[] array)
{
    //check if the array is empty
    if(array.length == 0)
    {
        //handle, whatever happens if the array is empty
        return -1; //maybe you should throw an exception here 
    }

    //storing the smallest found value, start with the first int in the array
    int smallest = array[0];

    //the iteration
    for(int i : array)
    {
        //check if the current checked value is smaller than the smallest found...
        if(i < smallest)
        {
            //...and if it is, set it as the smallest found value
            smallest = i;
        }
    }
    //finally, return the smallest value
    return smallest;
}

This should solve your current problem, but in most cases i'd rather recommend to use a pre sorted array or list instead. If the data in it is already stored in ascending order, the first element would always be the lowest and the last element always the highest value.

Answer 3

This method takes an infinite unknown variable quantity of parameters by using varargs as it's argument. Combining all the parameters added from it's call from main into an array of the same type. This was designed to account for mutability of the original method call in main. Finally, returning the smallest integer of all the parameters.

I'm a fairly new programmer, second year into computer science, and I'm not sure if this is even useful for anyone, but I hope it helps. Thanks to everyone here for your awesome tips and error catches. My issue was I forgot to import my Array class and one of my method calls from stream class was incorrectly named.

Lastly, for any veteran programmers out there, aside from this looking snappy and elegant, does this statement execute any faster than doing a simple foreach loop and comparing the num to the last smallest one?

   import java.util.Arrays;

   public class Test
   {
       public static void main(String[] args)
       {
           // Enter as many as you want here, can be more or less than three
           int num1 = 23;
           int num2 = 89;
           int num3 = 9;

           // Apply each variable as an argument for the method call
           int smallestNumber = smallest(num1, num2, num3);
           // Print out variable value to prove it works
           System.out.print(smallestNumber);
       }

       private static Integer smallest(int... nums)
       {
           // Found an elegant way to do the stubbed out block of code
           // I left the code down there to show what is going on here
           try
           {
               return Arrays.stream(nums).min().getAsInt();
           }
           catch (Exception e)
           {
               return null;
           }


           // The above code is essentially doing the below code
           /*try
           {
               // Initialize Variable to start of array
               int smallest = nums[0];

               // For:Each Loop: go through each parameter and assign it a local variable to compare with
               for(int i : nums)
               {
                   // compare if smaller
                   if(i < smallest)
                   {
                       // If true, set as smallest
                       smallest = i;
                   }
               }
               return smallest;
           }
           catch (Exception e)
           {
               return null;
           }*/
       }
    }