在java中打印数组中的每个单词

Question

public class namePrinting 
{
    //each name in a series of names
    public String[] names = {"Hello", "My", "Name", "Is", "Jose"};

    //the method for putting names in 
    public static void printNames(String [] namesArray) 
    {
        //go through each String in the array and then print each
        for(int i = 0; i <= namesArray.length; i++)
        {
            System.out.println(namesArray[i]);
        }
    }
    //print the names in this specific array
    printNames(names[]);
}

I'm pretty new to Java and was wondering what I was doing wrong? I just want to go through each string in the array and print each. I think the incorrect portion is at the bottom... is there a specific variable I am forgetting to put inside printNames?

Answer 1

Your code contains multiple errors:

1. You're using the names array in a static method, but the names themselves aren't static. Either remove the static from the method, or add static to the field.
2. printNames(names[]); is on class-level, which isn't possible. Method calls should be in a method or constructor.
3. names[] as parameter input isn't valid either. This should have been printName(names) instead.
4. <= should be < . Because the length is 5 for your array, but the indices are [0-4].

Try something like this (without static):

public class NamePrinter
{
    //each name in a series of names
    public String[] names = {"Hello", "My", "Name", "Is", "Jose"};

    //the method for putting names in 
    public void printNames(String [] namesArray) 
    {
        //go through each String in the array and then print each
        for(int i = 0; i < namesArray.length; i++)
        {
            System.out.println(namesArray[i]);
        }
    }

    public static void main(String[] a){
        NamePrinter namePrinter = new NamePrinter();

        //print the names in this specific array
        namePrinter.printNames(namePrinter.names);
    }
}

Try it online.

Or alternatively with static:

public class NamePrinter
{
    //each name in a series of names
    public static String[] names = {"Hello", "My", "Name", "Is", "Jose"};

    //the method for putting names in 
    public static void printNames(String [] namesArray) 
    {
        //go through each String in the array and then print each
        for(int i = 0; i < namesArray.length; i++)
        {
            System.out.println(namesArray[i]);
        }
    }

    public static void main(String[] a){
        //print the names in this specific array
        printNames(names);
    }
}

Try it online.

Answer 2

1. Change:

   for(int i = 0; i <= namesArray.length; i++)

   to:

   for(int i = 0; i < namesArray.length; i++) ,

   because last iteration causes ArrayIndexOutOfBoundsException (length of names array is equal to 5, but last index is equal to 4 - indices of an array start from 0).

2. Change printNames(names[]) to printNames(names) , because syntax that you have used is incorrect.

3. If you want to use names array in the static method, this array should be declared as static too, on the other hand, you can delete static keyword from printNames() method.

4. You can't call printNames(names) in the body of class as you did it. It should be put in some method or in the initialization block (I'm pretty sure that you should look to put it inside public static void main(String args[]) method.

Answer 3

To correct your code you have to :

• Call your printNames method from a main method
• Change your i <= namesArray.length to i < namesArray.length

Your code gonna look like this :

public class namePrinting 
{
    public static void printNames(String [] namesArray)
    {
        for(int i = 0; i < namesArray.length; i++)
        {
            System.out.println(namesArray[i]);
        }
    }

    public static void main(String[] args) {
        String[] names = {"Hello", "My", "Name", "Is", "Jose"};
        printNames(names);
    }
}

Try it online!

But to simplify your code you can use foreach instead of for loop :

public static void printNames(String [] namesArray)
{
    for (String name: namesArray) {
        System.out.println(name);
    }
}

Try it online!

And if you use Java 8 or +, you can use Stream Api like this :

public static void printNames(String [] namesArray)
{
    Arrays.stream(namesArray).forEach(System.out::println);
}

Try it online!

Have fun ;)

Answer 4

1 Change printNames(names[]) to printNames(names)

2 Use public static String[] names = {"Hello", "My", "Name", "Is", "Jose"}; instead of public String[] names = {"Hello", "My", "Name", "Is", "Jose"};

3 Use for(int i = 0; i <= namesArray.length -1 ; i++) instead of for(int i = 0; i <= namesArray.length; i++)