Java Arrays vs C++ Arrays |
Generally
speaking, there is not much difference between the Java and C or C++ arrays. As a C
/ C++ programmer you will find it very
easy to understand and work with arrays in Java.
In C++, when we declare an array, storage for the array is allocated. In Java, when we declare an array, we really only declare a pointer or reference to an array; storage for the array itself is not allocated until we use the "new" keyword. This difference is elaborated below:
C++
into A[10]; // A is an array of length 10
A[0] = 5; // set the 1st element of array A
JAVA
int [ ] A; // A is a reference / pointer to an array
A = new int [10]; // now A points to an array of length 10
A[0] = 5; // set the 1st element of the array pointed to by A
In both C++ and Java we can initialize an array using values in curly braces. Here's the example
Java code:
int [ ] myArray = {13, 12, 11}; // myArray points to an array of length 3
// containing the values 13, 12, and 11
In Java, a default initial value is assigned to each element of a newly allocated array if no initial value is specified. The default value depends on the type of the array element as shown below:
In C++, when we declare an array, storage for the array is allocated. In Java, when we declare an array, we really only declare a pointer or reference to an array; storage for the array itself is not allocated until we use the "new" keyword. This difference is elaborated below:
C++
into A[10]; // A is an array of length 10
A[0] = 5; // set the 1st element of array A
JAVA
int [ ] A; // A is a reference / pointer to an array
A = new int [10]; // now A points to an array of length 10
A[0] = 5; // set the 1st element of the array pointed to by A
In both C++ and Java we can initialize an array using values in curly braces. Here's the example
Java code:
int [ ] myArray = {13, 12, 11}; // myArray points to an array of length 3
// containing the values 13, 12, and 11
In Java, a default initial value is assigned to each element of a newly allocated array if no initial value is specified. The default value depends on the type of the array element as shown below:
|
Type
|
Value
|
|
boolean
|
false
|
|
char
|
'\u0000'
|
|
byte, int, short, long, float, double
|
0
|
|
any reference type e.g. a class object
|
null
|
In Java, array bounds are checked and an out-of-bounds array index always causes a runtime error.
