Java: int[] array vs int array[] [duplicate]

问题

Possible Duplicate:
Difference between int[] array and int array[]

Is there a difference between

int[] array = new int[10];

and

int array[] = new int[10];

Both do work, and the result is exactly the same. Which one is quicker or better? Is there a style guide which recommends one?

回答1:

Both are equivalent. Take a look at the following:

int[] array;

// is equivalent to

int array[];

int var, array[];

// is equivalent to

int var;
int[] array;

int[] array1, array2[];

// is equivalent to

int[] array1;
int[][] array2;

public static int[] getArray()
{
    // ..
}

// is equivalent to

public static int getArray()[]
{
    // ..
}

回答2:

They are both basically same, there is no difference in performance of any sort, the recommended one however is the first case as it is more readable.

int[] array = new int[10];

FROM JLS:

The [] may appear as part of the type at the beginning of the declaration, or as part of the declarator for a particular variable, or both.

回答3:

From JLS http://docs.oracle.com/javase/specs/jls/se5.0/html/arrays.html#10.2

Here are examples of declarations of array variables that do not create arrays:

int[ ] ai;          // array of int
short[ ][ ] as;         // array of array of short
Object[ ]   ao,     // array of Object
        otherAo;    // array of Object
Collection<?>[ ] ca;        // array of Collection of unknown type
short       s,      // scalar short 
        aas[ ][ ];  // array of array of short

Here are some examples of declarations of array variables that create array objects:

Exception ae[ ] = new Exception[3]; 
Object aao[ ][ ] = new Exception[2][3];
int[ ] factorial = { 1, 1, 2, 6, 24, 120, 720, 5040 };
char ac[ ] = { 'n', 'o', 't', ' ', 'a', ' ',
                 'S', 't', 'r', 'i', 'n', 'g' }; 
String[ ] aas = { "array", "of", "String", };

The [ ] may appear as part of the type at the beginning of the declaration, or as part of the declarator for a particular variable, or both, as in this example:

byte[ ] rowvector, colvector, matrix[ ];

This declaration is equivalent to:

byte rowvector[ ], colvector[ ], matrix[ ][ ];

回答4:

Both are the same. I usually use int[] array = new int[10];, because of better (contiguous) readability of the type int[].

回答5:

No, there is no difference. But I prefer using int[] array as it is more readable.

回答6:

There is no difference between these two declarations, and both have the same performance.

回答7:

There is virtually no difference.

回答8:

In both examples, you are assigning a new int[10] to a reference variable.

Assigning to a reference variable either way will be equal in performance.

int[] array = new int[10];

The notation above is considered best practice for readability.

Cheers

来源：https://stackoverflow.com/questions/14559749/java-int-array-vs-int-array

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java

arrays

performance

definition