C type casts and addition precedence

Question

What's the precedence in the next expression?

item = (char*)heap + offset;

Is it (char*)(heap + offset) or ((char*)heap) + offset?

score 36 · Accepted Answer · edited Aug 03 '19 at 23:35

36

Cast trumps binary addition according to the precedence table.

Precedence Table

edited Aug 03 '19 at 23:35

Alexander Ushakov

answered Jul 28 '10 at 15:28

Jacob

score 8 · Answer 2 · answered Jul 28 '10 at 15:27

8

It's ((char *)heap) + offset. Casts have much higher precedence than addition.

answered Jul 28 '10 at 15:27

Jerry Coffin

2

This is quite correct, but if it's really unclear to the coder, then I'd recommend actually using the parentheses as shown here. – Steven Sudit Jul 28 '10 at 15:29
4

The problem rises when the original author coder doesn't have precedence order doubts in the case, but another maintenance coder has. – Spidey Apr 12 '12 at 18:59

score 2 · Answer 3 · answered Jul 28 '10 at 15:27

2

((char*)heap) + offset

answered Jul 28 '10 at 15:27

Ned Batchelder

score 1 · Answer 4 · edited Jun 27 '22 at 08:32

1

The cast is done first, since it has a much higher precedence.

You can look that up in the C precedence table:

edited Jun 27 '22 at 08:32

ib.

answered Nov 28 '19 at 13:39

Alexander Grass

4 Answers4