with this … In this tutorial, you will learn-
What is an array?
Array Variables
First Array Program
Java Array: Pass by reference
Multidimensional arrays
how this helps is that a variable can reference the index (the number in the bracket[]) for easy looping.
Array Variables
Using an array in your program is a 3 step process –
- Declaring your Array
- Constructing your Array
- Initialize your Array
- Declaring your Array
Syntax or Example:
- Constructing an Array
Example: Declaration and Construction combined
- Initialize an Array
Declaring and initialize an Array Example:
First Array Program
Step 1) Copy the following code into an editor. Step 2) Save , Compile & Run the code. Observe the Output Output: Step 3) If x is a reference to an array, x.length will give you the length of the array. Uncomment line #10. Save, Compile & Run the code.Observe the Output Step 4) Unlike C, Java checks the boundary of an array while accessing an element in it. Java will not allow the programmer to exceed its boundary. Uncomment line #11. Save, Compile & Run the code.Observe the Output Step 5) ArrayIndexOutOfBoundsException is thrown. In case of C, the same code would have shown some garbage value.
Java Array: Pass by reference
Arrays are passed to functions by reference, or as a pointer to the original. This means anything you do to the Array inside the function affects the original. Example: To understand Array are passed by reference Step 1) Copy the following code into an editor Step 2) Save, Compile & Run the code. Observe the Output Output:
Multidimensional arrays
Multidimensional arrays are actually arrays of arrays. To declare a multidimensional array variable, specify each additional index using another set of square brackets. When you allocate memory for a multidimensional array, you need only specify the memory for the first (leftmost) dimension. You can allocate the remaining dimensions separately. In Java, array length of each array in a multidimensional array is under your control. Example Output:
