java array Can you check if a value exists in a specific index?

int[ ] [ ] array = new int[3][3]; when If the value of array[1][2] exists, can we make it true if it does not exist?

2022-09-22 18:47

1 Answers

If you create an array of scalar types such as int, initialize the elements to zero.

On the other hand, created an array with the reference type, factors such as integer null to reset.

You can check if it is 0 or null.

jshell> int[][] array = new int[3][3]
array ==> int[3][] { int[3] { 0, 0, 0 }, int[3] { 0, 0, 0 }, int[3] { 0, 0, 0 } }

jshell> array[1][2]
$2 ==> 0

jshell> array[1][2] != 0
$3 ==> false

jshell> Integer[][] array2 = new Integer[3][3]
array2 ==> Integer[3][] { Integer[3] { null, null, null }, I ... [3] [3] { null, null, null } }

jshell> array2[1][2]
$5 ==> null

jshell> array2[1][2] != null
$6 ==> false

2022-09-22 18:47

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