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For Example


would use at most the first ten digits typed as the new value for i.

Here is an example to demonstrate the usage of printf and scanf functions

#include<conio.h>#include<stdio.h>void main() {// variable declaration int a;float x; char ch;char* str; // Enter dataprintf(“Input an integer”); scanf(“%d”,&a); printf(“\n Input a real number”);scanf(“%f”,&x); printf(“\n Input a character”);fflush(stdin); scanf(“%c”,&ch); printf(“\n Input a string” );fflush(stdin); scanf(“%s”,str); // Output the dataprintf(“\n Your data”); printf(“\n Integer: %d”,a);printf(“\n Float : %.2f”,x); printf(“\n Char: %c:,ch);printf(“\n String : %s”,str); }

(Function fflush are used to avoid stopping the reading process when meet one or more spaces)

There is one main problem with scanf function which can make it unreliable in certain cases. The reason being is that scanf tends to ignore white spaces, i.e. the space character. If you require your input to contain spaces this can cause a problem.

Scanf will skip over white space such as blanks, tabs and new lines in the input stream. The exception is when trying to read single characters with the conversion specifiers %c. In this case, white space is read in. So, it is more difficult to use scanf for single characters. An alternate technique, using getchar, will be described later.

Other input and output functions


The computer asks the user press a key. This key does not appear on screen. The syntax is:


getch() is used to terminate a program when the user press a key.


gets reads a line of input into a character array. The syntax is:



puts writes a line of output to standard output. The syntax is:

puts(name of string);

It terminates the line with a new line, '\n'. It will return EOF is an error occurred. It will return a positive number on success.

For using the statements mentioned above, you must declare the library<conio.h>.



C contains the following operator groups.

  • Arithmetic
  • Assignment
  • Logical/relational
  • Bitwise

Arithmetic operators

The arithmetic operators are +, -, /, * and the modulus operator %. Integer division truncates any fractional part. The expression x%y produces the remainder when x is divided by y, and thus is zero when y divide x exactly.The % operator cannot be applied to a float or double.

The binary + and – operators have the same precedence, which is lower than the precedence of *, / and %, which is turn lower than unary + and - . Arithmetic operators associate left to right.

Operator Meaning Data type of the operands Examples
- opposite integer, float int a, b; -12; -a; -25.6;
+ addition integer, float float x, y; 5 + 8; a + x;3.6 + 2.9;
- subtraction integer, float 3 – 1.6; a – 5;
* multiplication integer, float a * b; b * y; 2.6 * 1.7;
/ division integer, float 10.0/3.0; (= 3.33…) 10/3.0; (= 3.33…)10.0/3; (= 3.33…)
/ integer division integer 10/3; (= 3)
% modulus integer 10%3; (=1)

Assignment operators

These all perform an arithmetic operation on the lvalue and assign the result to the lvalue. So what does this mean in English? Here is an Example

Questions & Answers

find the 15th term of the geometric sequince whose first is 18 and last term of 387
Jerwin Reply
The given of f(x=x-2. then what is the value of this f(3) 5f(x+1)
virgelyn Reply
hmm well what is the answer
how do they get the third part x = (32)5/4
kinnecy Reply
can someone help me with some logarithmic and exponential equations.
Jeffrey Reply
sure. what is your question?
okay, so you have 6 raised to the power of 2. what is that part of your answer
I don't understand what the A with approx sign and the boxed x mean
it think it's written 20/(X-6)^2 so it's 20 divided by X-6 squared
I'm not sure why it wrote it the other way
I got X =-6
ok. so take the square root of both sides, now you have plus or minus the square root of 20= x-6
oops. ignore that.
so you not have an equal sign anywhere in the original equation?
is it a question of log
Commplementary angles
Idrissa Reply
im all ears I need to learn
right! what he said ⤴⤴⤴
what is a good calculator for all algebra; would a Casio fx 260 work with all algebra equations? please name the cheapest, thanks.
Kevin Reply
a perfect square v²+2v+_
Dearan Reply
kkk nice
Abdirahman Reply
algebra 2 Inequalities:If equation 2 = 0 it is an open set?
Kim Reply
or infinite solutions?
The answer is neither. The function, 2 = 0 cannot exist. Hence, the function is undefined.
Embra Reply
if |A| not equal to 0 and order of A is n prove that adj (adj A = |A|
Nancy Reply
rolling four fair dice and getting an even number an all four dice
ramon Reply
Kristine 2*2*2=8
Bridget Reply
Differences Between Laspeyres and Paasche Indices
Emedobi Reply
No. 7x -4y is simplified from 4x + (3y + 3x) -7y
Mary Reply
how do you translate this in Algebraic Expressions
linda Reply
Need to simplify the expresin. 3/7 (x+y)-1/7 (x-1)=
Crystal Reply
. After 3 months on a diet, Lisa had lost 12% of her original weight. She lost 21 pounds. What was Lisa's original weight?
Chris Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
At high concentrations (>0.01 M), the relation between absorptivity coefficient and absorbance is no longer linear. This is due to the electrostatic interactions between the quantum dots in close proximity. If the concentration of the solution is high, another effect that is seen is the scattering of light from the large number of quantum dots. This assumption only works at low concentrations of the analyte. Presence of stray light.
Ali Reply
the Beer law works very well for dilute solutions but fails for very high concentrations. why?
bamidele Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Introduction to computer science. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10776/1.1
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