Searching an array for a specific value

Question

So here's my dilemma, I'm trying to search an array for a specific value, but I'm getting an error that I don't know how to fix. Here's my current code:

import java.util.Arrays;

public class Marathon {

public static void main(String[] args)  {

    double[]    weeks = {2,4.66,7.33,10,12.66,15.33,18,20.66,23.33,26};
    double sum = 0;
    int length = weeks.length;

    for (double i : weeks)
        sum += i;

    System.out.println("What is the value for array element 2: " + weeks[1]);
    System.out.println("What is the list length: " + length);
    System.out.println("Sum of all miles run during the 10 week period: " + sum);
    System.out.println("Does the list contain a week with 4 miles: ");

    boolean retval = weeks.contains(4.00);
    if (retval == true) {
        System.out.println("10 is contained in the list");
       }
      else {
        System.out.println("10 is not contained in the list");
       }
    }
}

The error message I'm getting is as follows:

Cannot invoke contains(double) on the array type double[]   
Marathon.java/do while/src  line 18 Java Problem

Any help on this would be greatly appreciated! Thanks in advance.

arrays don´t have a `contains` method that they can invoke, that´s what the error is trying to tell you. — SomeJavaGuy, Apr 04 '16 at 14:47
So what's the proper/best way to search a single array for a specific value? — markus242005, Apr 04 '16 at 14:57

score 1 · Answer 1 · answered Apr 04 '16 at 15:04

You could do this with Java 8:

boolean retval = DoubleStream.of(weeks).anyMatch(i->i==10.0);

It transforms your array of double to DoubleStream. Afterwards it matches the stream against a predicate saying that i equals 10.0 for example.

I hope it helps.

score 0 · Answer 2 · answered Apr 04 '16 at 14:53

0

What you should know is that array in Java does not have method contains(). What you can do is to loop the array and compare the elements.

answered Apr 04 '16 at 14:53

Reed Grey

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Searching an array for a specific value

2 Answers2