of 19
7/27/2019 Programmin in C
1/19
PROGRAMING IN C
Tutorial
7/27/2019 Programmin in C
2/19
A Simple C program
#include
int main( ) {
printf("hello, world");
return 0;
}
7/27/2019 Programmin in C
3/19
Variables; Types and Type Declarations
#include
int main( ) {
int a, b, c, sum;
a = 1; b = 2; c = 3;
sum = a + b + c;
printf("sum is %d", sum);
return 0;
}
7/27/2019 Programmin in C
4/19
Variables; Types and Type
Declarations
7/27/2019 Programmin in C
5/19
Simple I/O getchar(), putchar(), printf ()
int main( ) {char c;
c = getchar( );
putchar(c);
getchar();
}
printf("hello, world");
printf("sum is %d", sum);
7/27/2019 Programmin in C
6/19
Simple I/O getchar(), putchar(), printf()
n = 511;
printf("What is the value of %d in octal?", n);
printf("%s! %d decimal is %o octal\n", "Right", n, n);
What is the value of 511 in octal? Right! 511 decimal is 777 octal
7/27/2019 Programmin in C
7/19
If - relational operators and compound
statements
if(expression) statement
== equal to!= not equal to
> greater than
< less than
>= greater than or equal to
7/27/2019 Programmin in C
8/19
If - relational operators and compound
statements
C guarantees that `&&' and `||' are evaluated left to right --we shall soon see cases where this matters.
if( c==' ' || c=='\t' || c=='\n' ) ...
Grouped together by {}
if (a < b) {
t = a;
a = b;
b = t;
}
7/27/2019 Programmin in C
9/19
Else Clause; Conditional Expressions
if (expression) statement1 else statement2
if (a < b)
x = a;
elsex = b;
expr1 ? expr2 : expr3
a
7/27/2019 Programmin in C
10/19
a common programming structure
if(...)
{...}
else if(...){...}
else if(...)
{...} else {...}
7/27/2019 Programmin in C
11/19
The Switch Statement ; Break ;
Continueswitch( c ) {
case 'a':
aflag++;
break;
case 'b':
bflag++;break;
case 'c':
cflag++;
break;
default:printf("%c?\n", c);
break;
}
7/27/2019 Programmin in C
12/19
While Statement; Assignment within
an Expression; Null Statement
while (expression) statement
int main( ) {char c;
while( (c=getchar( )) != '\0' )
putchar(c);
return 0;
}
7/27/2019 Programmin in C
13/19
for Statement
for( initialization; expression; increment)
statement
initialization;
while( expression ) {
statement
increment;
}
7/27/2019 Programmin in C
14/19
for Statement
sum = 0;
for( i=0; i
7/27/2019 Programmin in C
15/19
Arithmetic
x = a%b;
c = c + 'A' - 'a';
main( ) {
char c;
while( (c=getchar( )) != '\0' )
if( 'A'
7/27/2019 Programmin in C
16/19
Increment and Decrement Operators
int k=5;
x = ++k;
x = k++;
main( ) {
int c,n;
n = 0;
while( (c=getchar( )) != '\0' )
if( c == '\n' )
++n;printf("%d lines\n", n);
}
7/27/2019 Programmin in C
17/19
Arrays
int x[10];
x[0], x[1], x[2], ..., x[9]
main( ) {
int n, c;
char line[100];n = 0;
while( (c=getchar( )) != '\n' ) {
if( n < 100 )
line[n] = c;
n++;}
printf("length = %d\n", n);
}
7/27/2019 Programmin in C
18/19
Character Arrays; Strings
We can copy a character array s into another t like this:
main( ) {
int n;
char line[100];n = 0;
while( (line[n++]=getchar( )) != '\n' );
line[n] = '\0';
printf("%d:\t%s", n, line);
}
7/27/2019 Programmin in C
19/19
Example to count letters, digits and
others in a filemain( ) {
int let, dig, other, c;
let = dig = other = 0;
while( (c=getchar( )) != '\0' )
if( ('A'