Creation of Object Arrays in Java
In Java, creating an array of objects is a straightforward process, but it differs slightly from other languages like C . When you declare an array of objects using the syntax A[] arr = new A[4];, it conceptually creates an array of references (or pointers) to objects of type A.
To actually create and initialize the objects themselves, you need to manually assign each element of the array to a new instance of A:
<code class="java">A[] arr = new A[4]; for (int i = 0; i < 4; i++) { arr[i] = new A(); }</code>
This explicit allocation is necessary because in Java, arrays are not automatically initialized. By default, object references (like the elements of arr in the first example) are initialized to null. Therefore, you will encounter a null pointer exception when attempting to access a method or variable of an uninitialized object.
This approach may seem unconventional compared to C , where the syntax new A[4] allocates and initializes the objects in one step. However, Java's separation of array declaration and object initialization provides greater control and flexibility. It allows for flexibility in cases where you may not want to initialize all the objects in an array or need to populate the array dynamically.
The above is the detailed content of How Does Object Array Creation Differ in Java Compared to C ?. For more information, please follow other related articles on the PHP Chinese website!