pointer equation

Hi
in the code
[code]
{while ( (*s++ = *t++) != '\0');}
[\code]

i was wondering if both *t and *s are checked for the null. or is it just *t?

Quote:

---

Originally Posted by studentc

Hi
in the code
[code]
{while ( (*s++ = *t++) != '\0');}
[\code]

i was wondering if both *t and *s are checked for the null. or is it just *t?

---

Only the result of the expression is checked for the null character. The result of the expression is the value of *s. However, because the expression was assignment, it's a safe bet that *t and *s have the same value.

so
you mean to say
if there is an expression

a=b=c;

does that mean the result of the expression is a

Quote:

---

Originally Posted by studentc

so
you mean to say
if there is an expression

a=b=c;

does that mean the result of the expression is a

---

Yes.

Quote:

---

Originally Posted by studentc

so
you mean to say
if there is an expression

a=b=c;

does that mean the result of the expression is a

---

Yes, but after a has been assigned the value of b, which in turn has been assigned the value of c.

so is
a first assigned the value of b,
or b first assigned the value of c

Operator Precedence and Associativity

Assignment has right-to-left associativity.

gg

[EDIT]
Ignore the C++ operators in that table :)

b is assigned the value of c, then a is assigned the value of b. Assignment is performed right to left, so it would look like this if fully parenthesized:

Code:

---

(a = (b = c));

---