while (expression)
statement ;

or

while (expression)
{ 
statement1 ;
statement2 ;
……………
}

#include <16F877.h> //register definition file for 
#fuses HS,NOWDT               //a Microchip PIC16F877
#use delay(clock=10000000 //setup the RS232 port for standard output
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,stream=RS232,bits=8)

#include <stdio>

void main(void)
{
            char c;
            c = 0;
            printf("Start of program \n") ;
            while(c < 100)            //if c less than 100 then …
            {
                        printf("c = %d\n" , (int)c) ; //print c's value each
//time through the loop
                        c++ ;                                                   // increment c
            }
            printf(" End of program \n");                       //indicate that the
//program is finished
while(1)                      //because 1 is always TRUE , then just sit here 
   ; 
}

void main(void)
{
            while(input_b( )  & 0x02       // hangs here waiting while the 
;                                   // bit 1 of port B is high 
            While(1)                     //because 1 is always TRUE , then just set here …
                        ;
}

do
            statement ;

or

do
{
statement1;
statement2;
……………
}while(expression);

#include <16F877.h> //register definition file for 
#fuses HS,NOWDT   //a Microchip PIC16F877
#use delay(clock=10000000 //setup the RS232 port for standard output
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,stream=RS232,bits=8)
#include <stdio>
void main(void)
{
            char c;
            c = 0;
            printf("Start of program \n") ;

            do
            {
                        printf("c = %d\n" , (int)c) ; //print c's value each
//time through the loop
                        c++ ;                                       // increment c
            } while(c < 100);                                //if c less than 100 then
//repeat the operation 
            printf(" End of program \n");           //indicate that the
//program is finished
while(1)                      //because 1 is always TRUE , then just sit here 
                        ; 
}

for (expr1 ; expr2 ; expr3 ) 
statement ;

or

for (expr1 ; expr2 ; expr3 ) 
{
statement ;
statement ;
………….
}

expr1 ;
while(expr2)
{
            statement1;
            statement2 ;
            …….
            expr3 ;
}

#include <16F877.h> //register definition file for 
#fuses HS,NOWDT   //a Microchip PIC16F877
#use delay(clock=10000000 //setup the RS232 port for standard output
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,stream=RS232,bits=8)

#include <stdio>

void main(void)
{
char c;
            printf("Start of program \n") ;
for(c = 0; c < 100; c++) //if c less than 100 then
{
                        printf("c = %d\n" , (int)c) ; //print c's value each time 
// through the loop
                                                                        // c++ is executed before the
                                                                        //loop returns to top 
            printf(" End of program \n");           //indicate that the
//program is finished
while(1)                      //because 1 is always TRUE , then just sit here 
                        ; 
}

if (expression)
            statement ;

or

if (expression)
{
statement1 ;
            statement2 ;
            …………
}

if (expression)
            statement1 ;
else
            statement2 ;

or

if (expression)
{
statement1 ;
            statement2 ;
            …………
}
else
{
statement3 ;
            statement4 ;
            …………
}

if (expr1)
            statement1;
else if (expr2)
            statement2;
else if (expr3)
            statement3;
else
statement4;

#include <16F877.h> //register definition file for 
#fuses HS,NOWDT   //a Microchip PIC16F877
#use delay(clock=10000000 //setup the RS232 port for standard output
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,stream=RS232,bits=8)

#include <stdio>

void main(void)
{
char c;
            printf("Start of program \n") ;
for(c = 0; c < 100; c++) //while  c less than 100 then
{
            if (c < 33) 
                        printf("0<c<33   ");               //use if/else to show the rang of 
            else if( ( c>32) && (c < 66 ) )           //numbers that c is in 
                        printf("32<c<66   " ) ;
            else
                        printf("66<c<100    ");
                        printf("c= %d\n",(int)c;        //print c's value each time
//through the loop
            }

            printf(" End of program \n") ; // indicate that the program is finished 

while(1)                      //because 1 is always TRUE , then just sit here 
                        ; 
}

#include <16F877.h> //register definition file for 
#fuses HS,NOWDT   //a Microchip PIC16F877
#use delay(clock=10000000 //setup the RS232 port for standard output
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,stream=RS232,bits=8)

#include <stdio>

#define test_port input_b()
void main(void) 
{
            unsigned char cnt , bit_mask ; // variables
            port_b_pullups(TRUE);
            set_tris_b (0xFF) ; // set port B for all input

            bit_mask = 1 ; //start with lowest bit

            for (cnt=0;cnt<8;cnt++) //for loop to test 8 bits 
            {
                                    // the instructions below test port bits 
                                    // and print result
                        If(test_port & bit_mask)
                                    printf("Bit   %d is high.\n",(int)cnt);
                        else
                                    printf("Bit   %d is low.\n') , (int)cnt);

                        bir_mask <<= 1 ; // shift bit to be tested 
            }

            while(1) // because 1 is always TRUE , then just sit here …
                        ;
}