C and C++ Programming Tips

Tip	Author	Rating (votes)
gets is dangerous	carl johnson	7.6
do not use printf without %s to print a string	pavan kumar	7.5
Temporariless Swap	Guille	7.4
Comparisons in C\C++	Nikitas Angelinas	7.3
Rounding to an Integer	Gorn	7.3
logical error on division	M.Kumaran	7.3
assert() yourself!	Kevin Lam	7.2
Always write if statements with braces	Webmaster	7.1
Don't use strlen in a loop condition.	anonytmouse	7.0
When optimizing code, focus on algorithms first	Alex Allain	7.0
Passing array elements to functions	Umer khan	7.0
difference between int* p and int *p declaration	omprakash mishra	6.9
Multiply rather than Divide	Reese Moore	6.9
Solve Any Compiler Error Easily	Wajahat Karim	6.9
Better coding style for comparison	nids	6.9
Standard Loop Progression	Dazzle	6.9
The power of scanf()	Joanna	6.8
Common Optimization Tips	Travis Fischer	6.8
Keep a cool head when programming	Sentralia	6.8
High performance looping	Rachana	6.8
Keep fit to program better	Luna Man	6.8
Pointer Tips :-)	Jatin Gandhi	6.8
Converting numbers to Strings	Webmaster	6.7
C++ new does not return 0 on failure!	Are R. Svendsen	6.7
Initialise all variables before use	Mounish	6.7
Be organised	Prophet-Ex	6.7
Never do unary minus on sizeof	Vaibhav	6.7
Pointer Memory allocation	Krishnamoorthi	6.7
Fast multiplication	Jean-François Geyelin	6.7
Use ++ and --	Subyraj P.S	6.7

Effective Modularity in Programming	Sharma PCS	6.6
Flowcharts	ayyapparaju	6.6
The many meanings of NULL	Rajat Kochhar	6.6
Safely using strncpy	oliv29	6.5
Avoid void main()	Webmaster	6.5
initalization of objects	mohit dhawan	6.5
Dont't use scanf() when reading sentences	Romnico	6.5
clean up after cin (C++)	Major_Small	6.5
Write it out on paper	rakesh kumar	6.5
loop condition	Krishna	6.4
Logic	Hardi Pertel	6.4
Be careful when storing pointers inside unions	singam kiran reddy	6.4
Code Optimization Tips	Basker Swaminathan	6.4
Be careful about array size when u are using strcp	Bhushan Verma	6.4
Clever ways to avoid using if statements	A. Karthick Pandia Samy	6.4
think before you code	Timofei Gerasimov	6.4
Programming Tips	Jatin Gandhi	6.3
Pointer arithmetic hack	Vivek Ahlawat	6.3
Unexpected struct behavior in Borlands Turbo C++ 3	Raza Sayed	6.3
Effective use of ==	Er.Nathan	6.3
Make libraries for yourself	Valseedian	6.2
use of ! operator	mrinal jha	6.2
Initialise all variables	Jia.Lu	6.2
getchar() returns an int	Rob	6.2
compiler tip	Julian Sutherland	6.2
Fix all compiler warnings	rickey	6.1
backups using CVS save you lot of space	Leif	6.1
Free The Memory That You Use	Udhaya Kumar.D	6.1
Use makefile	cjediknight	6.1
Use Good Variable And Function Names	prog-bman	6.1

Error handling for new	Upesh Jindal	6.1
Do NOT always check for NULL! (C++)	Kevin Lam	6.1
gets() is bad.	Sean	6.1
Fastest raise to power.	Ezzetabi	6.0
Run code in Different compilers	Naren Varma	6.0
Prefer pre-increment and pre-decrement	Karl	6.0
Pointer arithmetic trickiness	vishesh jain	6.0
Test pieces of your code early	Hardi Pertel	6.0
Understanding the win32 data types	Muhammad Shahid	6.0
Reuse Old Code	Timofei Gerasimov	6.0
Rounding a floating point number to a near-fraction	Steven	6.0
Dynamic memory allocation of 2d arrays	nandam	6.0
Make backups	Vox	6.0
Tips for writing programs for beginners	pradeep	6.0
Modifying const variables	Wiro Sableng	6.0
String to integer	Mayur Avhad	6.0
Use const variables as function parameters when po	beyonddc	5.9
Use STL containers instead of C arrays	Sang-drax	5.9
Executing system commands	Sean	5.9
Turn on all compiler warnings	Maragato	5.8
Always check for NULL (in C)	Webmaster	5.8
Use multiple files	Thantos	5.8
Use <constant> == <value>	Webmaster	5.8
Goto vs. Higher-level control structures	Sean	5.7
Commenting out code with the preprocessor	Webmaster	5.7
Use templates to prevent memory leakage	Kunal	5.7
Don't use fflush(stdin)	Shakti	5.7
Use the Appropriate Variables	Mahesh Kumar.S	5.6
beware of loop invarinats	Iain	5.6
Member Functions are inline by default (C++)	Ash	5.6

Avoid memory wastage	Arthi	5.6
Get a copy of the standard	Thantos	5.6
take advantage of array indicies	Dave	5.6
pre & post increment & decrement operators	jay	5.6
Turn off optimization when debugging	Ashok Kumar	5.5
Doing calculations	Linuxguru	5.5
Make pointer and reference arguments const	Akshay	5.5
Comment!	VOX	5.5
Give Proper Names to Your Variables	Maragato	5.5
char *pa; and char a[];	avdtech	5.5
Indent your Program	Prashant Sahay	5.5
match the out side world ideas to logical designin	mady	5.4
Put braces around if statement code, part 2	PING	5.3
Compiling 32-bit code on a 64-bit machine	vinay Kumar	5.0
Cute but dangerous code, finding the larger integer without using comparisons	Prakash Samy	5.0
Don't modify a variable more than once in a single statement	Ganga R Jaiswal	5.0
Operator Associativity and Hierarchy	Avinash	5.0
What is pointer arithmetic?	Umer khan	4.6
Decompose before you code	Abhinandan Pandey	4.5
finding size of variable without using sizeof()	Rajesh punia	4.0
swap with out using temporary	raghava	4.0
Arguments for Main	Sajan	3.7
Automatic Array initialisation	kedar	3.7
creating a messagebox on Windows	Amarjeet Kawathe	3.5
Check the return value of scanf( )	citizen	3.2
Be careful of Magic behaviour due to compilers	manik	3.0
increment and decrement on pointer	RAJKUMAR	3.0
Checking if two arrays are equal	Unnikrishnan T A	0.7
Assigning a char array to another char array	Brian Plummer	0.5
Increment and decrement counters with rollover	Lee Walker	0.0

Using _strtime and _strdate to get the time	Ali Jafar	0.0
One instruction per line	Ludovic Flender	0.0
Use preincrement with iterators	Dirk Tjantele	0.0
Use virtual functions instead of type checking	Sajan	0.0
Why you can't dereference a void* pointer	ashish mathur	0.0
Don't increment the same variable multiple times in one statement	sidra	0.0
Never return a non-const pointer to a data member!	hussain hani	0.0
Display Date and Time in C++	Govind	0.0
Long variable names	Carl	0.0
take care while using new and delete	rajender	0.0
Operator precedence shortcut	sai shanker	0.0

Protect your data

USB flash drives are convenient, portable, and very easy to lose. Which is a problem, especially if they're carrying sensitive data. Fortunately Windows 7 has the solution: encrypt your documents with an extension of Microsoft's BitLocker technology, and only someone with the password will be able to access it. Right-click your USB flash drive, select Turn on BitLocker and follow the instructions to protect your private files.

PROTECT YOUR DATA: Your USB flash drives can easily be encrypted with BitLocker

Pin a drive to the taskbar

The taskbar isn't just for apps and documents. With just a few seconds work you can pin drive icons there, too.

Right-click an empty part of the desktop, select New > Text File, and rename the file to drive.exe. Drag and drop this onto your taskbar, then delete the original file.

Right-click your new "drive.exe" taskbar button, then right-click its file name and select Properties. Change the contents of both the Target and Start In boxes to point at the drive or folder of your choice, perhaps click Change Icon to choose an appropriate drive icon, and you're done - that drive or folder is now available at a click.

Customise the log-on screen

Changing the Windows log-on screen used to involve some complicated and potentially dangerous hacks, but not any more - Windows 7 makes it easy.

First, browse to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Authentication\LogonUI\Background in REGEDIT, double-click the DWORD key called OEMBackground (not there? Create it) and set its value to 1.

Now find a background image you'd like to use. Make sure it's less than 256KB in size, and matches the aspect ratio of your screen as it'll be stretched to fit.

Next, copy that image into the %windir%\system32\oobe\info\backgrounds folder (create the info\backgrounds folders if they don't exist). Rename the image to backgroundDefault.jpg, reboot, and you should now have a custom log-on image.

Alternatively, use a free tweaking tool to handle everything for you. Logon Changer displays a preview so you can see how the log-on screen will look without rebooting, while the Logon Screen Rotator accepts multiple images and will display a different one every time you log on.

Windows Tricks and Shortcuts

Startup Screen

1. Create a 320x400 bitmap in the root directory and name it LOGO.SYS
2. You can use LOGOW.SYS file in the Windows directory as a starter

Logoff Screens

1. There are many system file that constitutes Lofoff screen.
2. They are actually bitmaps 320x400 that just have a different extension
3. The hidden file in the root directory LOGO.SYS is the startup logo.
4. There are two files in the Windows directory.
5. LOGOW.SYS is the Wait while Shutting down ... screen.
6. LOGOS.SYS is the You may now shut-off or Reboot screen.
7. Make two new image files of your chice in Paint and name it as LOGOW.SYS and LOGOS.SYS and replce the actual windows file by this two.
8. But make sure they should be of the same size

Lock a folder in windows XP

To Lock a folder in windows XP without any software. Follow the steps Below.

1. Make a Folder in C drive rename it as "abc" without quotes.
2. Now open Command Prompt from Start Menu.
3. Type "attrib +s +h C:\abc" without quotes and press enter.
4. This command will Make your folder invisble and it can not be seen even in hidden files and folders
5. To make it visible again type "attrib -s -h C:\abc"
6. You can lock any other folder also by changing the location C:\abc to address of your folder.

Magic Bottle Trick

Effect: 

The magician asks for a volunteer from the audience who looks inside a bottle to make sure it's a normal, empty container. 

The volunteer returns the bottle and then examines a magic wand to ensure it is normal. 

The magician drops the wand into the bottle (noting how easily it falls in).

He/she turns bottle over and lets go of the wand.  

The wand magically remains suspended in the bottle.

Supplies:

~a magic wand (could use a pencil instead) that is taller than the bottle (when you drop the wand into the bottle, part of it should still be sticking up through the opening.
~a bottle that has an opening large enough to fit the wand in (but not too big).  The bottle cannot be see-through
~an eraser

If you don't have a bottle that is dark, you can put some dark paint inside the bottle and shake it around so the inside is painted.

Cut a piece off the eraser, just large enough to wedge the wand into the opening of the bottle.  The eraser is what makes the trick work!

Secret:

Pass the bottle to the volunteer and ask them to make sure its empty.

Take back the bottle and give your friend the wand.  Meanwhile, slip the piece of eraser into the bottle without anyone seeing (you can have it in your pocket until this point).   You'll need to practice this a few times.

Take the wand back and drop it into the bottle.

Pick up the wand and bottle and turn them VERY SLOWLY upside down (mumble all sorts of enchantments while you're doing this).  Pull on the wand slightly when the bottle is turning over so the piece of eraser gets wedged into the opening (you'll need to practice this a few times too).

Let go of the wand... PRESTO!  It doesn't fall out.

Slowly turn upright again.  Let go of everything and PRESTO the wand remains suspended in the bottle (it doesn't fall back down).

To remove the wand, push it slightly to release the rubber and then take it out.