6. What is the purpose of using do-while loop?

Ans:

A do-while loop is used to ensure that the statements within the loop are executed at least once.

Ex - 1:  What is the output?
main()
{
int i=0;
for(i=0;i<20;i++)
{
switch(i)
case 0:i+=5;
case 1:i+=2;
case 5:i+=5;
default i+=4;
break;}
printf("%d,",i);
}
}

a) 0,5,9,13,17
b) 5,9,13,17
c) 12,17,22
d) 16,21
e) Syntax error

Ans. (d)

Ex - 2:  What is the output?
main()
{char c=-64;
int i=-32
unsigned int u =-16;
if(c>i)
{printf("pass1,");
if(c<U)
printf("pass2");
else
printf("Fail2");
}
else
printf("Fail1);
if(i<U)
printf("pass2");
else
printf("Fail2")
}

a) Pass1,Pass2
b) Pass1,Fail2
c) Fail1,Pass2
d) Fail1,Fail2
e) None of these

Ans. (c)