Comments on: 3.4 — Sizeof, comma, and arithmetic if operators http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/ Tue, 07 Feb 2012 12:30:29 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: bacia http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-96545 bacia Sun, 04 Dec 2011 12:09:48 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-96545 return x, y; would this only return y? return x, y;

would this only return y?

]]> By: bla http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-89971 bla Tue, 10 Aug 2010 11:05:53 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-89971 It's a bit confusing that a lower precedence corresponds to a higher precedence level here. Is that the standard way of saying it? It’s a bit confusing that a lower precedence corresponds to a higher precedence level here. Is that the standard way of saying it?

]]> By: Reshure http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-69178 Reshure Sun, 27 Sep 2009 17:55:58 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-69178 Are you using the comma operator too when initializing multiple variables in one statement? <pre> int x = 5, y = 3; </pre> Are you using the comma operator too when initializing multiple variables in one statement?

int x = 5, y = 3;
]]> By: jeremy http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-67735 jeremy Thu, 03 Sep 2009 23:11:33 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-67735 Is it bad form to place the assignment inside the arithmetric if? eg.: <pre>(x > y) ? (z = x) : (z = y);</pre> It compiles fine with Codeblocks and GCC. This seems more elegant IMHO. Is it bad form to place the assignment inside the arithmetric if? eg.:

(x > y) ? (z = x) : (z = y);

It compiles fine with Codeblocks and GCC.
This seems more elegant IMHO.

]]> By: mwgamera http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-61987 mwgamera Fri, 05 Jun 2009 22:08:42 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-61987 It's not a function, sizeof is an operator. Its value is determined in compile time. It’s not a function, sizeof is an operator.
Its value is determined in compile time.

]]> By: mwgamera http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-61985 mwgamera Fri, 05 Jun 2009 22:00:03 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-61985 Arithmetic if is a construct that takes a number and executes different things depending on that number beeing less, equal or greater than zero. Such statement can be found in FORTRAN. But there is no <em>arithmetic</em> if in C++! A ternary operator employs your usual <em>logical</em> condition (i.e. if not zero). Arithmetic if is a construct that takes a number and executes different things depending on
that number beeing less, equal or greater than zero. Such statement can be found in FORTRAN.
But there is no arithmetic if in C++!
A ternary operator employs your usual logical condition (i.e. if not zero).

]]> By: manju23reddy http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-60928 manju23reddy Sun, 17 May 2009 03:39:56 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-60928 hi, using sizeof function will resolve during 1. runtime 2. compile time 3. pre-compile time plz answer me hi,
using sizeof function
will resolve during
1. runtime
2. compile time 3. pre-compile time

plz answer me

]]> By: Alex http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-35928 Alex Tue, 30 Dec 2008 05:10:34 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-35928 The only place I see the comma operator commonly used is inside loops, to increment multiple variables, especially for loops. We cover for loops in more detail in <a href="http://www.learncpp.com/cpp-tutorial/57-for-statements/" rel="nofollow">Chapter 5.7 -- For statements</a>. Using the comma operator is a useful way to increment or decrement multiple variables in a single expression. For example: <pre> nX++, nY++, nZ--; </pre> Due to the particular syntax constraints on for loops, all your variables have to be modified in a single expression -- this allows you to do that. The only place I see the comma operator commonly used is inside loops, to increment multiple variables, especially for loops. We cover for loops in more detail in Chapter 5.7 — For statements.

Using the comma operator is a useful way to increment or decrement multiple variables in a single expression. For example:

nX++, nY++, nZ--;

Due to the particular syntax constraints on for loops, all your variables have to be modified in a single expression — this allows you to do that.

]]> By: Steve http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-35911 Steve Tue, 30 Dec 2008 02:18:58 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-35911 Hey, whats the point of the comma operator if all it does is evaluate to the rightmost operand? Hey, whats the point of the comma operator if all it does is evaluate to the rightmost operand?

]]> By: Marvin http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/comment-page-1/#comment-18617 Marvin Tue, 10 Jun 2008 03:35:34 +0000 http://www.learncpp.com/cpp-tutorial/34-sizeof-comma-and-arithmetic-if-operators/#comment-18617 In your first example, shouldn't the \t be t only? It wouldn't output like that unless I changed it. Using Geany as IDE and gcc as compiler. [ You are correct. I've updated the example. Thanks! -Alex ] In your first example, shouldn’t the \t be t only?

It wouldn’t output like that unless I changed it.

Using Geany as IDE and gcc as compiler.

[ You are correct. I've updated the example. Thanks! -Alex ]

]]>