You asked: How do you initialize an array in Java without size?

How you will Declare an array in java without size? You can do it with an ArrayList, It’s a collection framework used in Java that serves as dynamic data. ArrayList array = new ArrayList(); Here is an example code Java Array without a size.

How do you initialize an empty array in Java?

new Keyword to Declare an Empty Array in Java

The syntax of declaring an empty array is as follows. Copy data-type[] array-name = new data-type[size]; //or data-type array-name[] = new data-type[size]; There are two major ways to declare an empty array in Java using the new keyword that is as follows.

How do you initialize an array without size?

For example, you can initialize an array without specifying the number of elements: int MyNumbers[] = {1,2,3,4,5,6,7,8,9,10}; The compiler is smart enough to count how many elements you put inside the braces, and then the compiler makes that count the array size.

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Can you declare an array without array size?

Answer: No. It is not possible to declare an array without specifying the size. If at all you want to do that, then you can use ArrayList which is dynamic in nature.

How do you fill an empty array in Java?

Populate an Array in Java

  1. Use { } to Populate an Array in Java.
  2. Use the for Loop to Populate an Array in Java.
  3. Use the Arrays.copyOf() Method to Fill Element in a Java Array.
  4. Use the Arrays.fill() Method to Fill Elements in a Java Array.

How do you initialize a string array as null in Java?

For a String[] to have no values, you would initialize it as new String[0] . If you want the String array to contain elements, but all those elements are referencing null , then you need to access each element and set its value to null .

How do you take an array without knowing its size?

If you really don’t know the length of the array before you need to create it – for example, if you’re going to ask the user for elements, and then get them to enter some special value when they’re done, then you would probably want to use a List of some kind, such as ArrayList .

How do you initialize an array in Java?

We declare an array in Java as we do other variables, by providing a type and name: int[] myArray; To initialize or instantiate an array as we declare it, meaning we assign values as when we create the array, we can use the following shorthand syntax: int[] myArray = {13, 14, 15};

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How do you take an input of an unknown size array?

You can take string from user without defining size of an array by using char pointer.

  1. char* s = calloc(1,sizeof(char));
  2. char t;
  3. int len;
  4. while(scanf(“%c”, &t)==1)
  5. {
  6. if(t== ‘n’)
  7. break;
  8. len = strlen(s);

Can you declare an array without assigning the size of an array Java?

You can dynamically declare an array as shown below. i do not want the array to have a specific size because each time the size must be different. Arrays in Java have fixed size. Once declared, you cannot change it.

Is it necessary to use new operator to initialize an array in Java?

Array can be initialized when they are declared. Array can be initialized using comma separated expressions surrounded by curly braces. It is necessary to use new operator to initialize an array.

How do you declare an array in Java dynamically?

Initialize a Dynamic Array

  1. public class InitializeDynamicArray.
  2. {
  3. public static void main(String[] args)
  4. {
  5. //declaring array.
  6. int array[];
  7. //initialize an array.
  8. array= new int[6];

How do you autofill an array in Java?

int[] array = new int[5]; Arrays. fill(array, -1); To fill 2-dimensional array, you can apply the above method to each single dimensional array by iterating. but for multidimensional array you will have to use a loop.

How do you fill an array?

Using the fill() method

The fill() method, fills the elements of an array with a static value from the specified start position to the specified end position. If no start or end positions are specified, the whole array is filled. One thing to keep in mind is that this method modifies the original/given array.

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How do you fill an array with a value in Java?

How to Fill (initialize at once) an Array in Java?

  1. Using for loop to fill the value.
  2. Declare them at the time of the creation.
  3. Using Arrays. fill()
  4. Using Arrays. copyOf()
  5. Using Arrays. setAll()
  6. Using ArrayUtils. clone()
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