an saurus

What is more efficient i++ or ++i?

Exact Duplicate: Is there a performance difference between i++ and ++i in C++? Exact Duplicate: Why should I use ++i? Exact Duplicate: Difference between i++ and ++i in a loop? What is more efficient i++ or ++i? I have only used this in Java and C/C++, but I am really asking for all languages that this is implemented in. In colleg...

Why can't I do ++i++ in C-like languages?

Half jokingly half serious: why can't I do ++i++ in C-like languages, specifically in C#? I'd expect it to increment the value, use that in my expression, then increment again. ...

Incrementing in C++ - When to use x++ or ++x?

Hello, I'm currently learning C++ and I've learned about the incrementation a while ago. I know that you can use "++x" to make the incrementation before and "x++" to do it after. Still, I really don't know when to use which... I've never really used "++x" and things always worked fine so far, but when should I use it? Exemple : In a fo...

c++

Why doesn't changing the pre to the post increment at the iteration part of a for loop make a difference?

Why does this int x = 2; for (int y =2; y>0;y--){ System.out.println(x + " "+ y + " "); x++; } prints the same as this? int x = 2; for (int y =2; y>0;--y){ System.out.println(x + " "+ y + " "); x++; } As far, as I understand a post-increment is first used "as it is" ...

C programming ++ operator

Why does this code always produce x=2? unsigned int x = 0; x++ || x++ || x++ || x++ || ........; printf("%d\n",x); ...

c

Question about post-increment operator

Hi guys, Why does the following code int i = 1; System.out.print(i += i++); System.out.print(i); output 2 two times instead of 3 for the 2nd print? Could somebody please shed some light on it? Thanks. ...

explain working of post and pre increment operator in Java

can you explain me the output of this in case of Java int a=5,i; i=++a + ++a + a++; i=a++ + ++a + ++a; a=++a + ++a + a++; System.out.println(a); System.out.println(i); The output is 20 in both cases ...

Is the behavior of return x++; defined?

If I have for example a class with instance method and variables class Foo { ... int x; int bar() { return x++; } }; Is the behavior of returning a post-incremented variable defined? ...

c++

return

Follow-up. Is return reference to x++ defined?

I recently asked the question http://stackoverflow.com/questions/2380803/is-the-behavior-of-return-x-defined The result was about what I expected, but got me thinking about a similar situation. If I were to write class Foo { ... int x; int& bar() { return x++; } }; Where bar now returns an int reference, is this behav...

whether a language needs preIncrement (++x) and postIncrement (x++)

i have never seen the usecase for preincrement and postincrement in actual code. The only place i see them most often are puzzles. My opinion is, it introduces more confusion rather than being useful. is there any real use case scenario for this can't this can be done by using += y = x++ y = x x += 1 ...

programming-languages

increment

post increment operator java

I can't make heads or tails of the following code from "java puzzlers" by joshua bloch. public class Test22{ public static void main(String args[]){ int j=0; for(int i=0;i<100;i++){ j=j++; } System.out.println(j); //prints 0 int a=0,b=0; a=b++; System.out.println(a); System.out.println(b); //prints 1 } } I ca...

operator-keyword

Post-Increment Operator: Unexpected Behavior

Possible Duplicate: Could anyone explain these undefined behaviors (i = i++ + ++i , i = i++, etc) My code is as follows: #include <stdio.h> int main() { int x = 10, y = 0; x = x++; printf("x: %d\n", x); y = x++; printf("y: %d\n", y); } Given the nature of post-increment, I would expect the following output: x: 10...

c

gcc

Does implementation of ++i vs. i++ vary from language to language?

I recently read: "The expressions (++i) and (i++) have values and side effects. The side effect is that the value in i is increased by 1. The value of (i++) is the value before the increment and the value of (++i) is the value after the increment, but whether the increment or the evaluation takes place first, is not part of C." I know t...

C# difference between arr[0]++ and ++arr[0]

In C#, is there a difference between the code (all in one statement, not part of a larger one) arr[0]++; and ++arr[0]; I fully understand, that in C / C++ / Objective-C, that this would not do the same thing, first case would get the value at arr's 0th index and increment that value by one, while the second one, increases the pointer va...

How is *it++ valid for output iterators?

In example code, I often see code such as *it++ for output iterators. The expression *it++ makes a copy of it, increments it, and then returns the copy which is finally dereferenced. As I understand it, making a copy of an output iterator invalidates the source. But then the increment of it that is performed after creating the copy would...

is `x-- > 0 && array[x]` well defined behavior in c++?

can i use x on both sides of a boolean expression when I post-increment it on the left side? the line in question is: if(x-- > 0 && array[x]) { /* … use x … */ } is that defined through the standard? will array[x] use the new value of x or the old one? ...

c++

undefined-behavior