Can you initialize an array with a variable

Keep in mind that the size of your array object will be the number of elements you specify inside the curly brackets. Therefore, that array object is of size three. This method work for objects as well. If we wanted to initialize an array of three Strings, we would do it like this:. Check out our hands-on, practical guide to learning Git, with best-practices, industry-accepted standards, and included cheat sheet. Stop Googling Git commands and actually learn it!

Note : If you're creating a method that returns an initialized array, you will have to use the new keyword with the curly braces. When returning an array in a method, curly braces alone won't work:. If you're declaring and initializing an array of integers, you may opt to use the IntStream Java interface:.

The IntStream interface has a range method that takes the beginning and the end of our sequence as parameters. Keep in mind that the second parameter is not included, while the first is. Initializing an array after a declaration: An array can also be initialized after declaration.

Initializing an array and assigning values: An array can also be initialized during declaration. Keep Exploring. Related Courses. Learn in-demand tech skills in half the time. Early Access Courses. Assessments New. Free Trial New. For Business. For Educators. Become an Affiliate. Terms of Service.

Notice that the third element of foo is specified foo[2] , the second one is foo[1] , since the first one is foo[0]. If we write foo[5] , we would be accessing the sixth element of foo , and therefore actually exceeding the size of the array. This can create problems, since accessing out-of-range elements do not cause errors on compilation, but can cause errors on runtime.

The reason for this being allowed because index checking slows down program execution. At this point, it is important to be able to clearly distinguish between the two uses that brackets [] have related to arrays.

They perform two different tasks: one is to specify the size of arrays when they are declared; and the second one is to specify indices for concrete array elements when they are accessed. Do not confuse these two possible uses of brackets [] with arrays. The main difference is that the declaration is preceded by the type of the elements, while the access is not. Multidimensional arrays can be described as "arrays of arrays". For example, a bi-dimensional array can be imagined as a two-dimensional table made of elements, all of them hold same type of elements.

Table represents a bi-dimensional array of 3 per 5 elements of type int. Multidimensional arrays are not limited to two indices i. They can contain as many indices as needed.

Although be careful: the amount of memory needed for an array increases exponentially with each dimension. Declares an array with an element of type char for each second in a century. This amounts to more than 3 billion char! So this declaration would consume more than 3 gigabytes of memory! And such a declaration is highly improbable and it underscores inefficient use of memory space. At the end, multidimensional arrays are just an abstraction for programmers, since the same results can be achieved with a simple array, by multiplying its indices:.

With the only difference that with multidimensional arrays, the compiler automatically remembers the depth of each imaginary dimension. The following two pieces of code produce the exact same result, but one uses a bi-dimensional array while the other uses a simple array:.

None of the two code snippets above produce any output on the screen, but both assign values to the memory block called jimmy in the following way:. Note that the code uses named constants for the width and height, instead of using directly their numerical values. This gives the code a better readability, and allows changes in the code to be made easily in one place.