Java array is not iterable

Java – How to Convert Java Array to Iterable?

A quick guide to convert an array to iterable in java using Stream api with examples programs in two ways.

1. Overview

In this tutorial, We will learn how to convert java array to iterable in different ways with example programs.

First we will go thorough the basic one how to iterate over the array values. Next, how to convert the array to Iterable using legacy java api and finally using java 8 api for java array iterator.

Bonus section on how to convert string to iterable with a delimiter.

2. Create a iterator over the array using loops

Running a for loop over a array to create iterable logic to get the each value from array based on the index.

3. Convert Java Array to Iterable using legacy java before JDK 8

First we will convert the array to list using Arrays.asList() method. Next, convert list to Iterable in java using
list.iterator() method.

Finally, iterate the iterator over the while loop to get the all the values.

Array to Iterable Example:

4. Convert Java Array to Iterable Using Java 8 Stream

In the above section, we called Arrays.asList() method to convert the array to List. But, now will use another method from java 8 stream api Arrays.stream(array) method which takes input array and returns a Stream of array type.

Arrays.stream() method provides the arrays to access the stream api and use the power of parallel execution on larger arrays.

But for now, after getting the Stream object then you need to call the iterator() method on stream to convert Stream to iterable.

Do not worry, if you are new to the java 8, the below program is break down into multiple steps. And also provided a single line solution.

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Java — How to Convert Java Array to Iterable?

A quick guide to convert an array to iterable in java using Stream api with examples programs in two ways.

1. Overview

In this tutorial, We will learn how to convert java array to iterable in different ways with example programs.

First we will go thorough the basic one how to iterate over the array values. Next, how to convert the array to Iterable using legacy java api and finally using java 8 api for java array iterator.

2. Create a iterator over the array using loops

Running a for loop over a array to create iterable logic to get the each value from array based on the index.

package com.javaprogramto.arrays.toiterabale; /** * * Array Iterate example using loops * * @author javaprogramto.com * */ public class ArrayIterate < public static void main(String[] args) < // string array String[] names = new String[] ; // iterating array over its values. for(int index=0; index < names.length ; index++) < System.out.println(names[index]); >> >

3. Convert Java Array to Iterable using legacy java before JDK 8

First we will convert the array to list using Arrays.asList() method. Next, convert list to Iterable in java using list.iterator() method.

package com.javaprogramto.arrays.toiterabale; import java.util.Arrays; import java.util.Iterator; import java.util.List; /** * * Example to convert Java Array to Iterable before Java 8 * * @author javaprogramto.com * */ public class JavaArrayToIterableExample < public static void main(String[] args) < // string array String[] names = new String[] ; // string array to list conversion List namesList = Arrays.asList(names); // List to iterable Iterator it = namesList.iterator(); // printing each value from iterator. while(it.hasNext()) < System.out.println(it.next()); >> >

4. Convert Java Array to Iterable Using Java 8 Stream

In the above section, we called Arrays.asList() method to convert the array to List. But, now will use another method from java 8 stream api Arrays.stream(array) method which takes input array and returns a Stream of array type.

Arrays.stream() method provides the arrays to access the stream api and use the power of parallel execution on larger arrays.

But for now, after getting the Stream object then you need to call the iterator() method on stream to convert Stream to iterable.

Do not worry, if you are new to the java 8, the below program is break down into multiple steps. And also provided a single line solution.

import java.util.Arrays; import java.util.Iterator; import java.util.stream.Stream; /** * * Example to convert Java Array to Iterable using Java 8 Arrays.stream() * * @author javaprogramto.com * */ public class JavaArrayToIterableExampleJava8 < public static void main(String[] args) < // string array String[] names = new String[] ; System.out.println("Multi line solution"); // Convert string array to Stream Stream namesList = Arrays.stream(names); // Stream to iterable Iterator it = namesList.iterator(); // printing each value from iterator. while(it.hasNext()) < System.out.println(it.next()); >// singel line System.out.println("\nIn single line"); Arrays.stream(names).iterator().forEachRemaining(name -> System.out.println(name)); > >

Multiline and single line solutions provide the same output. If you are going to use in the realtime project then use it as single line statement as you want to fell like expert and take the advantage of stream power.

Multi line solution john Amal Paul In single line john Amal Paul

5. Bonus — Convert String to Iterable

Applying iterable on string is quite simple if you have understood the above code correctly. What we need is now to convert the String to String array with space or if the string has any delimiter.

public class JavaStringToIterableExampleJava9 < public static void main(String[] args) < // string String numbers = "1 2 3 4 5 6"; // string to string array String[] numbersArray = numbers.split(" "); System.out.println("Multi line solution"); // Convert string array to StreamStream numbersList = Arrays.stream(numbersArray); // Stream to iterable Iterator it = numbersList.iterator(); // printing each value from iterator. while(it.hasNext()) < System.out.println(it.next()); >// singel line System.out.println("\nIn single line"); Arrays.stream(numbersArray).iterator().forEachRemaining(name -> System.out.println(name)); > >

Multi line solution 1 2 3 4 5 6 In single line 1 2 3 4 5 6

6. Conclusion

In this article, you’ve seen how to convert the Array to iterable and get the each value from iterator using legacy and new java 8 api.

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A quick guide to convert an array to iterable in java using Stream api with examples programs in two ways.

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Solve the Can Only Iterate Over an Array or an Instance of Java.Lang.Iterable Error in Java

1. Can Only Iterate Over an Array or an Instance of java.lang.iterable
2. Solve the Can Only Iterate Over an Array or an Instance of java.lang.iterable Error Using Iterator()

We will learn about the Java error Can only iterate over an array or an instance of java.lang.iterable . We will see why this error occurs and the solution to it.

So without any further delay, let’s dive in.

Can Only Iterate Over an Array or an Instance of java.lang.iterable

This error is a compile time error, and it’s just as it says. It occurs when there is a problem with the iteration of an array or an instance.

While programming, the user tries to make things easier for themselves, and while doing so, the user uses loops. However, using loops is not always the correct answer.

The error can only iterate over an array or an instance of java.lang.iterable doesn’t mean that it stops the user from using a loop on an array or an instance. It means that a loop is used that doesn’t complement its conditions — for example, the for or foreach loop.

Solve the Can Only Iterate Over an Array or an Instance of java.lang.iterable Error Using Iterator()

In the case of loops, if a foreach loop is used, we have to explicitly type our iterations as sometimes foreach can cause this error to occur. We can do that by using Iterator .

Another way is to use a simple for or while loop.

Here is a simple example of explicitly iterating an array using an Iterator with a while loop. Here we will use ArrayList to demonstrate Iterator() .

An ArrayList is used here because Iterator() is a method of the ArrayList class.

A while loop is used here to make things easier. This is because while using other loops, for example, for and foreach , the Iterator() method does not work correctly.

Since Iterator() is part of a collection method, it works properly with specific loops, like the while loop.

import java.util.ArrayList; import java.util.Iterator; import java.util.List; import java.util.function.Consumer;  public class Main   public static void main(String[] args)    ListInteger> Num = new ArrayList<>(); //ArrayList is used here  Num.add(1);  Num.add(2);  Num.add(3);  Num.add(4);   IteratorInteger> value = Num.iterator(); //Here is the use of Iterator()  while (value.hasNext()) //hasNext() is used to loop. It is a method of Iterator()    System.out.println(value.next());  >  > > 

Haider specializes in technical writing. He has a solid background in computer science that allows him to create engaging, original, and compelling technical tutorials. In his free time, he enjoys adding new skills to his repertoire and watching Netflix.

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