So I've created my own class with 5 private fields: Each is an array with a pre-set length. It's my way of creating a table, where each array is a column, and they have pre-set lengths because not every cell will contain an element (So, not using anything dynamic).
Anyway, my question is: Can I check to see if a specific cell of a specific array contains "null"? Using .equals(null) gives a nullpointerexception :(
When you call .equals(...) you call a method of the object. If it is null, it has no method. Therefore null check like this:
if (myArray[position] == null) {
....
}
don't do .equals(null) but == null:
if( the_array[i] == null ) {
//...
}
Think about build a table by a bidimensional array. Example:
TheClass my_array[][] = new TheClass[10][5];
you should use
if (cell[i] == null){
}
since you are testing for reference equality. And in the case where cell[i] is actually null, null doesnt have an equals method.
Mixed up for loops and null construct
for(Integer ints : intNum) {
if(intNum != null) {
//valid
}
}
I'm more curious as to why your making 5 arrays? Have you heard of multidimensional arrays? Maybe that's what you really need in this case.
an array like this fx: int[][] arrayName = new int[3][3];
Would represent an array of 3 rows and 3 columns in each.
Maybe you alrdy knew that, but it just seems weird to me to make five different arrays if you just want a table-like structure.
