Creating array in Java

[khushi sharma]

What is the difference between following 2 approaches in creating an array.
Which is preferred depending on the use?

Approach 1:


int a[]= new int[5];                        
      a[0] = 98;
             a[1] = 97;
                            a[2] = 99;
                            a[3] = 94;
                            a[4] = 96;

Approach 2:
int a[]={98,97,99,94,96};

[Liutauras Vilda]

I'd say stick to second approach in this kind of situation. It is way more concise, more readable and has less places to go wrong, i.e.: by mistyping index.

Write angle brackets after the data type, and not the variable name.

Better:
int[] numbers

Worse:
int numbers[]


Put spaces around '=', put spaces after ','.

Better:
int[] numbers = {1, 2, 3, 4};

Worse:
int a[]={98,97,99,94,96};

Noticed variable name? Instead 'a', I've got 'numbers'. Better than 'a', but not very concrete. loterryNumbers would be better. Don't have 'a', 'b', 'z' as variable names (in most cases), they mean nothing.

[khushi sharma]

ok thanks

[Sayali pawar]

khushi sharma wrote:What is the difference between following 2 approaches in creating an array.
Which is preferred depending on the use?

Approach 1:


int a[]= new int[5];                        
      a[0] = 98;
             a[1] = 97;
                            a[2] = 99;
                            a[3] = 94;
                            a[4] = 96;

Approach 2:
int a[]={98,97,99,94,96};

There should be no difference as far as I know. Yet approach 2 is better looking, in my opinion.

[Campbell Ritchie]

Sayali pawar wrote:. . . There should be no difference as far as I know. . . .

The first approach is not only more time‑consuming, but it error‑prone, as Liutauras has hinted. The first approach has the risk that the number of elements is not exactly the same as the length of the array, which you won't find out about until runtime when either you suffer an out of bounds exception (more elements than spaces) or a null pointer exception (arrays of referene types only: more space than elements). The array initialiser guarantees that the size of the array and the number of elements will be the same.
The better looks of the second approach are accompanied by better behaviour
But both have the style error that the [] are after the name of the array. Also, as Liutauras said, a is a very bad identifier.