# Tag: assignment-operator

## r – Understanding exactly when a data.table is a reference to (vs a copy of) another data.table

The Question : 203 people think this question is useful I’m having a little trouble understanding the pass-by-reference properties of data.table. Some operations seem to ‘break’ the reference, and I’d like to understand exactly what’s happening. On creating a data.table from another data.table (via <-, then updating the new table by :=, the original table

## Why don’t Java’s +=, -=, *=, /= compound assignment operators require casting?

The Question : 3690 people think this question is useful Until today, I thought that for example: Was just a shortcut for: But if we try this: Then i = i + j; will not compile but i += j; will compile fine. Does it mean that in fact i += j; is a shortcut

## Why don’t Java’s +=, -=, *=, /= compound assignment operators require casting?

The Question : 3689 people think this question is useful Until today, I thought that for example: Was just a shortcut for: But if we try this: Then i = i + j; will not compile but i += j; will compile fine. Does it mean that in fact i += j; is a shortcut

## Why don’t Java’s +=, -=, *=, /= compound assignment operators require casting?

The Question : 3689 people think this question is useful Until today, I thought that for example: i += j; Was just a shortcut for: i = i + j; But if we try this: int i = 5; long j = 8; Then i = i + j; will not compile but i +=